SERVICE MANUAL
VL BOILER BASE SERIES
CONVECTION STEAMERS
(GAS, ELECTRIC, DIRECT AND REGENERATED)
VL2GPS
ML-52391
VL2DPS
VL2DMS
VL2DAS
VL2DSS
VL3DPS
VL3DMS
VL3DAS
VL3DSS
VL2RPS
VL2RMS
VL2RAS
VL2RSS
VL3RPS
VL3RMS
VL3RAS
VL3RSS
ML-52749
ML-52750
ML-52751
ML-52752
ML-52753
ML-52754
ML-52755
ML-52756
ML-52757
ML-52758
ML-52759
ML-52760
ML-52761
ML-52762
ML-52763
ML-52764
VL2GMS ML-52388
VL2GAS
VL2GSS
VL3GPS
ML-52390
ML-52389
ML-52395
VL3GMS ML-52392
VL3GAS
VL3GSS
VL2EPS
VL2EMS
VL2EAS
VL2ESS
VL3EPS
VL3EMS
VL3EAS
VL3ESS
ML-52394
ML-52393
ML-52741
ML-52742
ML-52743
ML-52744
ML-52745
ML-52746
ML-52747
ML-52748
VL2GPS SHOWN
- NOTICE -
This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified. If you have attended a Vulcan Service School for this
product, you may be qualified to perform all the procedures
described in this manual.
This manual is not intended to be all encompassing. If you have
not attended a Vulcan Service School for this product, you should
read, in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do
not have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.
Reproduction or other use of this Manual, without the express
written consent of Vulcan, is prohibited.
A product of VULCAN-HART
Form 24650 (May 1999)
LOUISVILLE, KY 40201-0696
VL SERIES STEAMERS
Direct Steam Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Regenerated Steam (Older Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Heater Contactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Heating Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Thermal Switch - Prevent and Automatic Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Water Level Gauge Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Steam Gate Valve(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
ELECTRICAL OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Water Level Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Solid State - Low Level Cut-off & Differential Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Electro Mechanical - Low Level Cut-off & Differential Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Gas Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Electric Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Schematics, Gas Steamers, Boiler Controls
VL2G AND VL3G - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Manual Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Electronic Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Manual Ignition, Csd-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Electronic Ignition, Csd-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Wiring Diagrams, Gas Steamers, Boiler Controls
VL2G AND VL3G - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Manual Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Electronic Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Manual Ignition, Csd-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Electronic Ignition, Csd-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Schematics, Electric Steamers, Boiler Controls
VL2E AND VL3E - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Auto Blowdown, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Auto Blowdown, Cal-code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Wiring Diagrams, Electric Steamers, Boiler Controls
VL2E AND VL3E - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Auto Blowdown, Standard Controls (Contactor - 1 Std.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Auto Blowdown, Standard Controls (Contactors - 2 Std.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Manual Blowdown, Cal-code Controls (Contactors - 1 Std. 1 Aux.) . . . . . . . . . . . . . . . . . . . . . . 68
Auto Blowdown, Cal-code Controls ( Contactors - 1 Std. 1 Aux.) . . . . . . . . . . . . . . . . . . . . . . . . 70
Auto Blowdown, Cal-code Controls (Contactors - 2 Std. 2 Aux.) . . . . . . . . . . . . . . . . . . . . . . . . 72
Manual Blowdown, Cal-code Controls (Contactors - 2 Std. 2 Aux.) . . . . . . . . . . . . . . . . . . . . . . 74
Wiring Diagrams, Electric Heater Circuits
VL2E AND VL3E - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Schematic and Wiring Diagrams, Direct Steamers, Cabinet Base
VL2D AND VL3D - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Wiring Diagrams, Regenerated Steamers, Boiler Controls
VL2R AND VL3R - Prevent, Automatic, Standard and Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Schematic and Wiring Diagrams - Compartment Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Prevent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
© VULCAN 1999
Page 3 of 88
VL SERIES STEAMERS - GENERAL
GENERAL
Boiler Code Descriptions
INTRODUCTION
Vulcan-Hart incorporates redundant controls in
compliance with California Code (Cal-Code) and
CSD-1 as an option on steam equipment when
required by state and/or local building code
requirements. Descriptions of the codes are listed
below.
Steam Cooking
Large capacity pressure steamers offer an efficient
way to produce a wide variety of foods in small
portions or larger batches. Steamers can be used to
cook fresh foods, blanch foods for complete cooking
later or will steam defrost and cook frozen foods.
Cooking with steam assures the food will retain its
maximum color, flavor and nutritional value with the
least expenditure of energy and labor.
Cal-Code Construction - Redundant controls in the
electrical safety circuits that, if tripped, must
manually be reset after the condition causing the trip
subsides. These controls consist of one dual
function water level cycling and low level cut off
control and one single function low water level cut-
off control (Aux - LLCO) and a high pressure relief
switch in conjunction with a mechanical pressure
relief valve.
Compartment Pan Capacity
PANS PER
COMPARTMENT
DEPTH
(INCHES)
SIZE
CSD-1 Construction - Redundant controls in the
electrical safety circuits that, if tripped, must
manually be reset after the condition causing the trip
subsides. These controls consist of one dual
function water level cycling and low level cut off
control and one single function low water level cut-
off control (LLCO) and a high pressure relief switch
in conjunction with a mechanical pressure relief
valve. Additionally, both circuits have individual
indicator lights that will illuminate for a visual
verification of the shutdown mode.
4
6
8
6
12" x 20"
12" x 20"
12" x 20"
*18" x 20"
6.0
4.0
2.5
1.0
* Remove center support for 18x20 inch pans
Cal-Code and CSD-1 construction both require
operator intervention in the event of a shutdown.
CSD-1 is more informative by using indicator lights
to show which safety system was shutdown.
Model Designations
V L X X XX
Cooking Control Types:
PS - Prevent Steam
AS - Automatic Steam
SS - Standard Steam
MS - Manual Steam
WATER CONDITIONING
Furnishing the boiler with soft water to reduce scale
formation is important. Scale formation will reduce
steam output, cause premature component failure,
and shorten equipment life. Most water supplies
contain scale producing minerals such as Calcium
and Magnesium. As steam is generated, the
minerals remain and dissolve into the water. As the
concentration of these minerals increases past a
certain point, they precipitate from the water and
coat the inside of the boiler, heating elements,
thermostat bulbs and water level probes. Because of
the high temperature of these surfaces, the
precipitated minerals bake onto them and become
very difficult to remove.
Heating System:
G - Gas
E - Electric
D - Direct
R - Regenerated
Number of Compartments
Large Capacity Pressure
Steamer
Vulcan
Page 4 of 88
VL SERIES STEAMERS - GENERAL
NOTE: Adaptors vary between manufacturers. An
This causes several problems:
example of one adaptor type is pictured below.
1. Reduce the heat transfer efficiency of the
heating system.
2. Cause premature failure of Electric heaters.
3. Water level probes will give false readings.
4. Thermostat bulbs will sense temperature
incorrectly.
These problems are common to any manufacturer's
steamer regardless of design, but they can all be
prevented by furnishing the boiler with soft water.
Vulcan recommends the water contain less than
60ppm of “total dissolved solids” (TDS) and have a
PH factor between 7 to 8. These water properties
can be achieved by using a properly maintained
water softener.
SPECIFICATIONS
Water Supply
Other chemical properties in water supplies can also
affect good steam generation and vary from within
each state and locality.
Supply pressure should be
In line strainer for supply line
Supply connection
Total dissolved solids (TDS)*
Total alkalinity
20-80 psig
(Not Supplied)
cold
The water level probes in the boiler use ions in the
water to detect the water level. Do not use fully
demineralized or de-ionized water since it is "non
conductive" and the water level can not be detected.
less than 60 ppm
less than 20 ppm
less than 13 ppm
less than 30 ppm
7 to 8
Silica
Chloride
NOTE: The use of strainers, or filters will not
remove minerals from the water.
PH factor
(*17.1 ppm = 1 grain of hardness)
Vulcan recommends that a local water treatment
specialist be consulted before the installation of any
steam generating equipment.
Steam Supply
Steamers that operate over a long period of time
without the benefit of a water softener, which have
developed a heavy scale build up, should be
cleaned before using a water softener.
Dry steam must be provided to the steamer for
suitable use. If the steam is heavy with condensate,
a Ball Float Trap must be used in the line and
plumbed in before the pressure reducing valve. To
ensure rapid heat up of heavy cold loads, the steam
supply line must be sized to maintain pressure as
outlined below.
TOOLS
Standard
Standard set of hand tools.
Volt-Ohm-Meter (VOM) with AC current tester.
DIRECT STEAM
STEAMERS
REGENERATED
STEAMERS -
(POTABLE)
OLDER MODELS
(*NON-POTABLE)
(Any quality VOM with a sensitivity of at least
20,000 ohms per volt can be used)
Gas leak checking equipment.
Gas pressure manometer
Temperature meter and thermocouple.
Special
Supply
Pressure Input
15 psi (min.)
15 psi (min.)
Flow Rate
50 lb. per hour per
compartment
125 lb. per hour
Pressure
Reducing Valve
Output
10 psi (furnished) set accordingly for good
steam generation (10-
CLR Treatment Kit - Used to remove
Calcium/Lime/Rust from a boiler (Contact
Vulcan Authorized Service Centers ).
12psi)
*Potable steam is not required for regenerated models but could
be used.
Adaptor to test thermocouple closed circuit
voltages (DC) on gas models with manual
ignition (purchase locally).
Page 5 of 88
VL SERIES STEAMERS - GENERAL
Gas Steamers
LINE PRESSURE
MANIFOLD
INPUT
AMPS
(MAX)
(INCHES W.C.)
PROPANE
PRESSURE
(BTU/HR)
LOAD
(INCHES W.C.)
NATURAL
(WATTS)
MAX
120V
60HZ
MODEL
VL2GPS
VL2GMS
VL2GAS
VL2GSS
VL3GPS
VL3GMS
VL3GAS
VL3GSS
NAT.
PROP. NAT.
PROP.
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
RECOMMEND
MIN
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
RECOMMEND
11.0
MIN
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
200,000 200,000
240,000 240,000
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
11.0 14.0
11.0 14.0
11.0 14.0
11.0 14.0
11.0 14.0
11.0 14.0
11.0 14.0
11.0 14.0
360
360
360
360
360
360
360
360
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
11.0
11.0
11.0
11.0
11.0
11.0
11.0
Electric Steamers
AMPERAGE
1 PHASE
3 PHASE
3 PHASE - 4 WIRE
TOTAL
KW
24*
36
MODEL
208V 240V 208V 240V 480V 220/380V & 240/415V
116 100
116 100
116 100
116 100
67
58
87
29
44
34
50
100
117
VL2EPS
42
48
116
58
58
29
44
67
34
50
24*
36
67
100
117
87
VL2EMS
VL2ESS
42
48
116
58
58
29
44
67
34
50
24*
36
67
100
117
87
42
48
116
58
58
29
44
67
34
50
24*
36
67
100
117
87
VL2EAS
*std
42
48
116
58
67
Page 6 of 88
VL SERIES STEAMERS - GENERAL
Also, the ignition control module
STEAMER OPERATION
ON/OFF/RESET switch must be in the ON
position to operate. This switch is located
on the upper left side of the electrical
control box for the ignition control module.
A red light will illuminate when the switch
is in the ON position. DO NOT ATTEMPT
TO MANUALLY LIGHT THE PILOT IN AN
AUTOMATIC TYPE IGNITION SYSTEM.
Ensure that all utility connections to the steamer
have been made and are turned on.
On models that are CSD-1 equipped, amber colored
lights for hi pressure and low water level will
illuminate and stay on until the boiler is full and the
manual reset switch pressed.
After the main power switch is turned ON
and the ignition control modules RESET
switch is in the ON position, sparking will
begin three seconds later to light the
standing pilot. If the pilot lights, a signal is
sent back through the ignition cable
indicating the presence of pilot flame and
sparking stops. If the water level in the
boiler has reached the minimum level, the
burners will ignite and begin to heat the
water in the boiler. After approximately 15
minutes, steam should be present for
cooking product. Observe that the boiler
pressure gauge indicates a steam
pressure of 9-11 psi for models with a
pressure regulating valve or 4-6 psi for
models without the valve. If a pilot flame
is not established immediately, sparking
will continue for 90 seconds. After that
duration, the ignition control module will
lock out and needs to be reset to start the
pilot and burner lighting cycle again.
Gas Powered Steam Boiler
5. Open the cabinet door and turn main power
switch ON. The red light will illuminate, water
will begin filling the boiler and the blowdown
solenoid valve will close. The boiler should fill,
in four to eleven minutes. Observe water level
gauge glass to verify that water is in boiler and
that the level in the gauge glass is about half
full. Both valves on gauge glass assembly must
be open to fill the gauge. Older models
equipped with a manual “ball” type blowdown
valve must be closed for the boiler to fill. The
cycling pressure switch will maintain the proper
steam pressure in the boiler by cycling the
heating system on and off to generate steam
pressure.
A. On Models with Manual Ignition - The
knob on the gas combination control valve
has three positions (On-Pilot-Off) for
control of main burners and pilot. Turn
knob on gas combination valve to PILOT
then depress and light pilot burner with a
lit taper. Maintain knob in depressed
position for about 30 seconds and release.
Observe that pilot burner flame stays on. If
the flame should go out, wait 5 minutes
before relighting.
Electrically Powered Steam Boiler
Open the cabinet door and turn main power switch
ON. The red light will illuminate, water will begin
filling the boiler and the blowdown solenoid valve
will close. The boiler should fill, in approximately 11
minutes. Observe water level gauge glass to verify
that water is in boiler and that the level in the gauge
glass is about half full. Both valves on gauge glass
assembly must be open to fill the gauge. Older
models equipped with a manual “ball” type
blowdown valve must be closed for the boiler to fill.
If the water level in the boiler has reached the
minimum level, the heater contactors will close, the
heaters will energize and begin to heat the water in
the boiler. After approximately 15 minutes, steam
should be present for cooking product. Observe that
the boiler pressure gauge indicates steam pressure
of 9-11 psi for models with a pressure regulating
valve or 4-6 psi for models without the valve.
Turn knob on gas combination control
valve to ON. If the water level in the boiler
has reached the minimum level, burners
will ignite and begin to heat the water in
the boiler. After approximately 15 minutes,
steam should be present for cooking
product. Observe that the boiler pressure
gauge indicates steam pressure of 9-11
psi for models with a pressure regulating
valve or 4-6 psi for models without the
valve.
B. On Models with Automatic Ignition -
The knob on the gas combination control
valve has two positions (On-Off) for
Regenerated Steam Powered Boiler
control of main burners and pilot. For the
automatic ignition system to work, the
knob must be set in the ON position or gas
for the pilot and main burners will not flow.
Open the cabinet door and turn main power switch
ON. The pilot light will illuminate, water will begin
filling the boiler and the blowdown solenoid valve
will close. Models equipped with a manual “ball
type” blowdown valve need to be closed for the
boiler to fill. The boiler should fill, in approximately
15 minutes.
Page 7 of 88
VL SERIES STEAMERS - GENERAL
Observe water level gauge glass to verify that water
Cooking Compartment Controls
is in boiler and that the level in the gauge glass is
about half full.
Close the compartment door and turn the screw
handle clockwise until the gasket touches the
compartment surface then ½ turn further to
adequately seal the compartment. If steam leaks
occur after compartment heat up and pressurization,
turn handle clockwise again to increase the sealing
force until the leak stops.
Both valves on the gauge glass assembly must be
open to fill the gauge. When the water reaches the
minimum level, the steam solenoid valve will open,
allowing steam to enter the steam coil in the heat
exchanger tank and begin heating the water. After
approximately 20 minutes, a sufficient amount of
pressurized steam should be present for cooking
product.
Proceed to the cooking compartment control
instructions that apply to the steamer in use.
Direct Steam Powered Cooker
1. Manual
1. Open the cabinet door and turn main power
switch ON.
A. Set the manual timer to the desired
cooking time. If preheating is desired,
allow five to ten minutes (recommended)
of additional time at the beginning of the
cook cycle. The length of time will vary
with the type, size, temperature and
condition (frozen or thawed) of the product
and must be determined from experience.
Pull the steam control arm handle forward
and lock it by pulling the handle down.
This closes the steam exhaust gate valve
and opens the steam inlet gate valve,
allowing steam to enter the compartment.
During preheat, cooler air and condensate
are exhausted from the compartment
through the steam trap (condenser) until
the temperature reaches 180°F, closing
the internal bellows. Throughout the
cooking cycle, the compartment pressure
should be 6 psi if equipped with a
A. The red light on the switch will illuminate.
B. If steam pressure is above the minimum
setting on the cooking compartment
pressure switch then the switch will close,
ready light will come ON and power to the
other controls will be supplied.
C. Observe that the steam pressure gauge in
the cabinet base, indicates 10-12 psi.
2. Steamer is ready to cook product.
Boiler Blowdown and Steamer Shut off
Turn the steamer off at least once daily and blow
down the boiler to remove sediments, scalants and
lime build-up in the boiler. Always blowdown the
boiler when it is under maximum pressure and no
steam is being used.
3. Automatic blowdown.
compartment pressure regulating valve.
On models without the compartment
pressure regulating valve, the
compartment pressure cycles with the
boiler pressure between 4 and 6 psi.
A. Newer Models - Open the cabinet door
and turn main power switch OFF. The
switches’ red light will go out, the
blowdown/drain solenoid valve will be de-
energized and the boiler will begin to
drain. The cold water condenser solenoid
will continue to operate, as needed, to
condense steam and to cool the water
going into the drain.
B. When the timer bell rings to signal the end
of a cook cycle, turn it OFF. Lift the steam
control arm handle to unlatch team control
arm. An internal spring will automatically
pull the arm to the rear. This closes the
steam inlet gate valve and opens the
B. Older Models - Turn power switch OFF
and depress blowdown timer button.
Blowdown timer will operate for 4 minutes.
At the end of blowdown, turn fill switch ON
and allow boiler to fill.
steam exhaust gate valve, allowing steam
and pressure to exit the compartment.
C. Wait approximately 30 seconds for the
steam to exhaust from the compartment
and to depressurize. Turn the screw
handle on the compartment door
counterclockwise until the gasket no
longer seals against the compartment
surface. After the remaining steam
escapes, move the latch paddle to the left
and open the door.
4. Manual blowdown.
A. All Models - Turn power switch OFF. Open
blowdown valve located on the bottom
front of the cabinet base. After the boiler
has completely drained, close blowdown
valve and turn fill switch to ON and allow
boiler to fill.
Page 8 of 88
VL SERIES STEAMERS - GENERAL
2. Standard
A. Set the timer to the desired cooking time.
3. Automatic
A. Set the timer to the desired cooking time.
The timer must be set past five minutes to
change the state of the timer control
micro switch contacts.
The timer must be set past five minutes to
change the state of the timer control micro
switch contacts. If preheating is desired,
allow five to ten minutes (recommended)
of additional time at the beginning of the
cook cycle. The length of time will vary
with the type, size, temperature and
B. Pull the steam control arm handle forward
and lock it by pulling the handle down.
This closes the steam exhaust gate valve
and opens the steam inlet gate valve,
allowing steam to enter the compartment.
condition (frozen or thawed) of the product
and must be determined from experience.
C. Press the compartment power switch to
supply power to the compartment controls.
The automatic compartment controls,
feature load compensated cooking time by
utilizing a thermal switch. With this
B. Pull the steam control arm handle forward
and lock it by pulling the handle down.
This closes the steam exhaust gate valve
and opens the steam inlet gate valve,
allowing steam to enter the compartment.
feature, when the compartment
C. Press the compartment power switch to
energize the timer and red light. The
balance of the cooking sequence is
automatic. During preheat, cooler air and
condensate are exhausted from the
compartment through the steam trap
(condenser) until the temperature reaches
180°F, closing the internal bellows.
temperature reaches 180°F (the
temperature at which preheating or
defrosting is complete) the red light will
then come on and the timer will start. For
a small food load, the delay time before
the timer starts might be a minute or less.
For a large food load, the delay time could
be four to five minutes. During preheat,
cooler air and condensate are exhausted
from the compartment through the steam
trap (condenser) until the temperature
reaches 180°F, closing the internal
bellows. Throughout the cooking cycle, the
compartment pressure should be 6 psi if
equipped with a compartment pressure
regulating valve. On models without the
compartment pressure regulating valve,
the compartment pressure cycles with the
boiler pressure between 4 to 6 psi.
Throughout the cooking cycle, the
compartment pressure should be 6 psi if
equipped with a compartment pressure
regulating valve. On models without the
compartment pressure regulating valve,
the compartment pressure cycles with the
boiler pressure between 4 and 6 psi.
D. Approximately one minute before timer
reaches zero the steam control solenoid is
energized to unlatch the steam control
arm. An internal spring will automatically
pull the arm to the rear. This closes the
steam inlet gate valve and opens the
steam exhaust gate valve, allowing steam
and pressure to exit the compartment.
When the timer reaches "0" the red light
shuts off and a buzzer sounds indicating
the end of the cook cycle. Turn the
D. Approximately one minute before timer
reaches zero the steam control solenoid is
energized to unlatch the steam control
arm. An internal spring will automatically
pull the arm to the rear. This closes the
steam inlet gate valve and opens the
steam exhaust gate valve, allowing steam
and pressure to exit the compartment.
When the timer reaches "0" the red light
shuts off and a buzzer sounds indicating
the end of the cook cycle. Turn the
compartment power switch OFF to silence
the buzzer and remove power from the
compartment controls.
E. Turn the screw handle on the
compartment door counterclockwise until
the gasket no longer seals against the
compartment surface. After the remaining
steam escapes, move the latch paddle to
the left and open the door.
compartment power switch OFF to silence
the buzzer and remove power from the
compartment controls.
E. Turn the screw handle on the
compartment door counterclockwise until
the gasket no longer seals against the
compartment surface. After the remaining
steam escapes, move the latch paddle to
the left and open the door.
Page 9 of 88
VL SERIES STEAMERS - GENERAL
D. Approximately one minute before timer
4. Prevent
A. Set the timer to the desired cooking time.
reaches zero the steam control solenoid is
energized to unlatch the steam control
arm. An internal spring will automatically
pull the arm to the rear. This closes the
steam inlet gate valve and opens the
steam exhaust gate valve, allowing steam
and pressure to exit the compartment.
When the timer reaches "0" the red light
shuts off and a buzzer sounds indicating
the end of the cook cycle. Turn the
compartment power switch OFF to silence
the buzzer and remove power from the
compartment controls.
The timer must be set past five minutes to
change the state of the timer control
micro switch contacts.
B. Pull the steam control arm handle forward
and lock it by pulling the handle down.
This opens the steam inlet gate valve,
allowing steam to enter the compartment.
C. Press the compartment power switch to
supply power to the compartment controls.
The prevent compartment controls feature
load compensated cook times by utilizing
a thermal switch. With this feature, when
the compartment temperature reaches
180°F (the temperature at which
E. Turn the screw handle on the
compartment door counterclockwise until
the gasket no longer seals against the
compartment surface. After the remaining
steam escapes, move the latch paddle to
the left and open the door.
preheating or defrosting is complete) the
red light will come on and the timer will
start. For a small food load, the delay time
before the timer starts might be a minute
or less. For a large food load, the delay
time could be four and five minutes.
During preheat, the steam exhaust
solenoid valve (N.O.) is open to allow the
full free venting of cooler air and
condensate from the compartment. When
the temperature reaches 180°F, the
exhaust solenoid valve is energized and
closes. The compartment should then
pressurize to 6 psi.
Page 10 of 88
VL SERIES STEAMERS - GENERAL
COMPONENT FUNCTION
CABINET BASE BOILER CONTROLS
Water Level
Gauge Assembly . . . . . . . . . . . . . . . Permits a visual confirmation the water level is being maintained in
boiler during operation. The correct water level is a point one-half of the
height of the glass. The manual valves at the top and bottom of this
assembly must be fully open and only closed if the glass tube is
damaged.
Water Level Control and
Level Sensing Probes . . . . . . . . . . . These controls allow water to enter the boiler to fill and maintain the
proper water level. They will also shut off the heat source to the boiler if
the water level drops too low. The water level control works by using
three different probe lengths to monitor the water level. The probes
consist of a high level (HL), low level (LL) and low water cut-off (LLCO).
Boiler Fill Solenoid Valve . . . . . . . . Admits water to the boiler when demanded by the water level control to
maintain the correct water level in the boiler.
Cold Water Condenser
Solenoid Valve . . . . . . . . . . . . . . . . . Allows cold water flow into the boiler blowdown drain box to condense
steam and cool the hot water before its discharge into the drain.
Cycling Pressure Switch . . . . . . . . . Controls boiler pressure between prescribed limits by turning the heat
source on and off.
High Limit Pressure Switch . . . . . . A switch of identical design to the cycling pressure switch but used as a
high limit. The pressure settings are at higher and lower limits than the
cycling pressure switch in order to turn off the heat source before the
boiler pressure reaches its limit and automatically resets after the
pressure drops below the lower limit set point.
Blowdown/Drain
Solenoid Valve . . . . . . . . . . . . . . . . . This valve is plumbed into the drain line of the boiler. Newer steamer
models will automatically blowdown when power is turned off by using a
normally open solenoid valve. Older models can have a solenoid valve
that is activated by depressing a separate blowdown timer button or
have a manual “ball” type valve.
Inlet Water Strainer . . . . . . . . . . . . . A strainer is used in the water inlet line to prevent foreign matter from
becoming lodged in the fill or cold water condenser solenoid valves and
to keep unwanted particles out of the system. A "Y" strainer should be
inserted upstream of the fill solenoid valve. On models using a direct
steam supply, a strainer is also used in the pressure regulating valve.
Power Switch . . . . . . . . . . . . . . . . . . When turned ON, power is supplied to the controls and the steam
generating process is started in the boiler. The power switch is located
on the front of the boiler control box.
Water Inlet Valve . . . . . . . . . . . . . . . The water inlet valve is used to stop water flow to the steamer when the
steamer is being serviced. Newer models will have a small Petcock type
valve while older models will be a “ball” type valve. This valve should
remain open during normal operation.
High Limit Thermostat . . . . . . . . . . A protective device that shuts off the heat source if the boiler
temperature exceeds a specified limit. All standard models are equipped
with a surface high limit.
Descaler . . . . . . . . . . . . . . . . . . . . . . Hangs submerged in water inside the boiler and is used to help control
boiler surface scaling. Two descalers are used in each boiler.
Page 11 of 88
VL SERIES STEAMERS - GENERAL
Handhole Cover Assembly . . . . . . . When unbolted and removed, allows internal examination and cleaning
of boiler shell and its components if required.
Boiler Pressure Gauge . . . . . . . . . . Indicates the amount of steam pressure in the boiler.
Check Valve . . . . . . . . . . . . . . . . . . . On models with the delime piping assembly option, prevents the ejection
of hot water and steam out of the delime funnel if the manual delime fill
valve were to be opened.
Delime Port Assembly . . . . . . . . . . . On models with the delime piping assembly option, allows the boiler and
other internal components to be delimed, easily removing calcium, lime
and rust build up.
Gas Pilot . . . . . . . . . . . . . . . . . . . . . Should always remain lit to light the main burners upon a call for heat
unless the steamer will not be in use for an extended period. If the pilot
flame goes out, wait 5 minutes before relighting.
Gas Burners . . . . . . . . . . . . . . . . . . . Heats the water in the boiler to generate steam.
Gas Combination Control Valve . . . A gas solenoid valve that opens to allow gas flow when a call for heat is
made. Also regulates the manifold gas pressure and supplies the gas
pilot.
Transformer . . . . . . . . . . . . . . . . . . . Provides 24VAC power to ignition control module. (gas models with
electronic ignition)
Ignition Control Module . . . . . . . . . Controls and monitors gas heating. Energizes pilot valve coil to supply
gas to pilot, generates spark to ignite gas at the pilot, monitors the
presence of flame and energizes main valve coil upon a call for heat to
supply gas to the main burners. The pilot and main solenoids are part of
the gas combination control valve. (gas models with electronic ignition)
Ignition Control Module
Reset (ON/OFF) Switch . . . . . . . . . . Controls power to the ignition control module and allows a reset of the
module if the gas ignition exceeds trial time. (gas models with electronic
ignition)
Heater Contactor
(Electric Boilers) . . . . . . . . . . . . . . . When coil is energized, supplies power to the electric heating elements.
Heating Elements
(Electric Boilers) . . . . . . . . . . . . . . . Heats the water in the boiler to generate steam.
Steam Header Assembly . . . . . . . . . Main steam supply line from the boiler to the steam header inlet in the
cooking control compartment.
Pressure Relief Valve . . . . . . . . . . . A mechanical device that opens to relieve steam pressure in the boiler if
the pressure exceeds 15 psi.
Compartment Pressure
Regulating Valve . . . . . . . . . . . . . . . Reduces steam pressure form the boiler or building steam (direct and
regenerated models) to supply the compartments a steam pressure of 6
psi. Standard on PS, option on MS, SS and AS compartment controls.
Page 12 of 88
VL SERIES STEAMERS - GENERAL
COOKING COMPARTMENT CONTROLS
The top half of the steamer consists of two to three separate cooking compartments depending on the model.
Each compartment functions independently with its own set of controls. Power is supplied to the controls through
the compartment power switch and the cooking timer control micro switch contacts. Prevent and Automatic
models have a load compensating thermal switch that prevents the controls from receiving power until the
compartment reaches 180°F to close the switch.
Compartment Power Switch . . . . . . Supplies power to the cooking compartment controls.
Cooking Light (Red) . . . . . . . . . . . . When lit, indicates steamer is in a cooking cycle. (All models except
manual)
Cooking Timer . . . . . . . . . . . . . . . . . Use to set desired cooking cycle time between 0-60 minutes. Energizes
the buzzer when time expires (All models except manual). On Prevent
models, also de-energizes the steam exhaust solenoid valve one minute
before the end of a cook cycle to allow compartment venting.
Buzzer . . . . . . . . . . . . . . . . . . . . . . . Signals end of a cook cycle, must be turned off manually. (All models
except manual)
Steam Exhaust Solenoid Valve . . . A normally open valve that allows full compartment venting of air and
condensate up to 180°F during compartment heat up and “limited free
venting” after energized by the closing of the thermal switch. The valve
remains closed to allow compartment pressurization to 6 psi until one
minute before the end of a cook cycle at which point the timer control
micro switch contacts (SW2) change state and de-energize the valve to
vent the compartment of pressure and steam. (prevent models)
Steam Header Inlet (manifold) . . . . Main steam supply line from the boiler for each cooking compartment.
Supplies steam to the manual steam gate valves.
Compartment Pressure Gauge . . . . Indicates the amount of steam pressure in cooking compartments.
Steam Control Arm Solenoid . . . . . When energized, engages the lift arm (plunger) to raise the steam
control arm off of the catch, allowing it to return to its rear position. This
closes the steam inlet gate valve and opens the steam exhaust gate
valve. (prevent, automatic and standard models)
Thermal Switch
(Load Compensator) . . . . . . . . . . . . Controls power to the preheat cycle components. Turns the cooking light
on, energizes the steam exhaust solenoid valve and energizes the
cooking timer motor to start timing, after the compartment reaches
180 F. (prevent and automatic models)
Steam Gate Valves . . . . . . . . . . . . . Manual valves actuated by the steam control arm. Allows steam to flow
into the cooking compartment through the inlet steam gate valve when
the arm is in a forward position and exhaust the steam through the
exhaust steam gate valve when the arm is at the rear. Prevent models
use a steam exhaust solenoid valve to exhaust the steam and a single
steam gate valve as the steam inlet. The automatic, standard and
manual models use one steam gate valve to exhaust the steam and
one additional steam gate valve as the steam inlet.
Steam Trap (Condenser) . . . . . . . . . Exhausts air and condensate from compartment during preheat until the
compartment temperature reaches approximately 180 F. The bellows
then close, stopping the exhaust. (all models except prevent)
Page 13 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
REMOVAL AND REPLACEMENT OF PARTS
COMPONENT LOCATIONS
Page 14 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
Page 15 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
COOKING COMPARTMENT CONTROLS - COMPONENT CONFIGURATIONS
1. Prevent
thermal switch, inlet steam gate valve, steam exhaust solenoid
(shown above) valve, steam control arm solenoid, timer, buzzer and power switch
with light. Does not use a steam trap.
2. Automatic
same as prevent except does not include steam exhaust solenoid
valve but does include an exhaust steam gate valve and two steam
traps.
3. Standard
4. Manual
same as automatic except does not include thermal switch.
manual and exhaust steam gate valves and a manual timer.
Includes two steam traps.
Page 16 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
4. Slide the glass tube upwards until the bottom of
WATER LEVEL CONTROLS -
LOW LEVEL CUT OFF AND
DIFFERENTIAL
the tube is clear of the fitting and lift it out.
5. When reinstalling the tube use new sealing
washers. Do not over tighten the packing nuts;
it could break the gauge glass.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
6. Open the top and bottom valves and check for
proper operation.
CYCLING AND HIGH LIMIT
PRESSURE SWITCHES
Solid State
1. Open the cabinet base doors.
(GAS AND ELECTRIC MODELS)
2. Remove the two screws at the top of the boiler
control box and allow cover to drop down.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
3. Water level control is mounted on the back
side of cover.
4. Disconnect lead wires from the board and
remove the water level control.
1. Open the cabinet base doors and remove the
left side panel.
5. Reverse procedure to install and check for
proper operation.
2. Remove the two screws at the top of the boiler
control box and allow cover to drop down.
Electro Mechanical
3. The pressure switches are located at the rear of
the box. The pressure switch on the right is the
cycling or primary control; the one on the left is
the high limit control. They are identical
1. Open the cabinet base doors.
2. Remove the two screws from the left and right
side of the water level control box and lift cover
off.
switches, differing only in their settings.
4. Remove the cover from the pressure switch
being replaced and disconnect the lead wires.
3. Disconnect lead wires from the control being
replaced and remove.
5. Disconnect the pressure fittings at the bottom
of the switch.
4. Reverse procedure to install and check for
proper operation.
6. Remove the mounting screws on the back side
of the control box and lift out the pressure
switch.
WATER LEVEL GAUGE
ASSEMBLY
7. Preset the new pressure switch to the
approximate cut-out (off) and cut-in (on) set
points before installing. See the boiler pressure
chart under “CYCLING AND HIGH LIMIT
PRESSURE SWITCHES (GAS AND
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
ELECTRIC MODELS)” in “SERVICE
PROCEDURES AND ADJUSTMENTS”.
8. Reverse procedure to install.
9. Adjust the pressure switch(s) final set points as
outlined under “CYCLING AND HIGH LIMIT
PRESSURE SWITCHES (GAS AND
ELECTRIC MODELS)” in “SERVICE
PROCEDURES AND ADJUSTMENTS” and
check for proper operation.
1. Open the cabinet base doors and remove the
right side panel.
2. Close the valve at the top and at the bottom of
the gauge assembly.
3. Unscrew the packing nuts at the top and bottom
of the glass tube.
Page 17 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
BOILER ASSEMBLY
HIGH LIMIT THERMOSTAT
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: SHUT OFF THE GAS BEFORE
1. Open the cabinet base doors.
SERVICING THE UNIT.
2. Electric models only - for gas models proceed
to step 3.
WARNING: ALL GAS JOINTS DISTURBED
DURING SERVICING MUST BE CHECKED FOR
LEAKS. CHECK WITH A SOAP AND WATER
SOLUTION (BUBBLES). DO NOT USE AN OPEN
FLAME.
A. Newer Models - are not equipped with a hi
limit thermostat but rely on the Hi limit
pressure switch instead.
B. Older Models - the high limit thermostat is
located behind the contactor box cover.
On electric boilers with two heating
elements, the thermostat is connected to
one of the heating element lugs. On
electric boilers with four heating elements,
the thermostat is located on an aluminum
plate between the center pair of elements
at the top of the elements. Remove the
thermostat lead wires and mounting nuts,
replace thermostat and check for proper
operation.
1. Blow down the boiler and allow to cool, if
necessary.
2. Ensure that all utilities to the steamer are off
and disconnected. Drain any excess water from
the boiler.
3. Disconnect the steam supply line, power leads
and drain lines from the cooking compartment
top to the boiler base.
4. Disconnect all plumbing connections and power
leads from the components inside the control
boxes that would obstruct the removal of the
boiler through the front of the base, then
remove those control boxes.
3. Gas Models only.
A. Remove the thermostat cover which is
located on the front of the boiler.
5. Disconnect the remaining plumbing and
electrical connections from the boiler to the
controls.
Disconnect the thermostat lead wires and
remove the nuts securing the high limit
thermostat to the boiler surface.
6. Remove the screws holding the flue and flue
collector to the base.
4. Reverse procedure to install and check for
proper operation.
7. Remove the anchor screws holding the boiler to
the frame. Slide the boiler forward. The burner
box, anchored only by the boiler, must be
prevented from sliding forward with the boiler.
8. Reverse procedure to install a new boiler and
check for leaks and proper operation.
Page 18 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
BOILER FILL AND COLD WATER
GAS COMBINATION CONTROL
CONDENSER SOLENOID VALVES
VALVE
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Turn off the water supply to the steamer.
WARNING: SHUT OFF THE GAS SUPPLY
2. Open the cabinet base doors and remove the
two screws at the top of the boiler control box
and allow cover to drop down. Both solenoid
valves are located side by side near the front of
the boiler control box with the boiler fill on the
right and the cold water condenser to the left.
BEFORE SERVICING THE UNIT.
WARNING: ALL GAS JOINTS DISTURBED
DURING SERVICING MUST BE CHECKED FOR
LEAKS. CHECK WITH A SOAP AND WATER
SOLUTION (BUBBLES). DO NOT USE AN OPEN
FLAME.
3. Disconnect the power lead wires from the
solenoid valve being serviced.
NOTE: Gas combination control valves are not
serviceable and should not be disassembled. Once
the problem has been isolated to this control,
replace it. Do not attempt to repair the assembly.
4. Disconnect the water lines for the valve being
serviced and remove the valve.
5. Reverse procedure to install.
1. Open the cabinet base doors and remove the
two screws at the top of the boiler control box
and allow cover to drop down.
PILOT AND THERMOCOUPLE
ASSEMBLY (GAS MODELS)
2. Disconnect electrical supply wires and conduit
running to the combination control valve.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
3. Disconnect the thermocouple lead (if
applicable), pilot gas supply tube from control
and pipe connections on each side of the
control.
4. Reverse procedure to install.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
5. Set manifold pressure as outlined under “GAS
MANIFOLD PRESSURE ADJUSTMENT” in
“SERVICE PROCEDURES AND
WARNING: ALL GAS JOINTS DISTURBED
DURING SERVICING MUST BE CHECKED FOR
LEAKS. CHECK WITH A SOAP AND WATER
SOLUTION (BUBBLES). DO NOT USE AN OPEN
FLAME.
ADJUSTMENTS”.
6. Check for proper operation.
1. Open the cabinet doors to access the pilot and
thermocouple assembly. The assembly is
located to the right of the center burner and
half way back from the front.
2. Disconnect thermocouple and pilot gas supply
tubing from the combination control valve.
3. Remove the two screws holding the pilot to its
bracket.
4. Replace the thermocouple or pilot assembly
and check for proper operation.
Page 19 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
4. Turn screw handle fully counterclockwise and
COMPARTMENT GASKET AND
remove from door.
DOOR SCREW NUT, DOOR AND
BUSHINGS
5. Remove screws mounting the pressure bar to
the backside of the compartment door.
NOTE: A compression spring is mounted behind
each screw. Set aside for reuse.
Gasket
6. Remove screws mounting the door screw nut
(bronze) to the backside of the compartment
door.
1. Open the compartment door to be replaced.
2. Remove screws securing the gasket retaining
plate to the gasket.
7. Reverse procedure to install and check for
proper operation.
Door and Bushing
1. Open the compartment door to be replaced.
2. Remove the right side pan support inside the
compartment.
3. Remove the four bolts inside the compartment
that secure the block hinges to the exterior side
of the compartment.
3. Lift the gasket off the inner door plate.
CAUTION: Door is extremely heavy and will drop
when bolts are removed.
4. Position the new gasket on the inner door plate
and reverse procedure to install.
NOTE: Damage to the gasket sealing surface, such
as nicks or cuts, will cause steam leakage.
Door Screw Nut
1. Open compartment door to be serviced.
2. Turn screw handle fully clockwise to extend
inner door plate assembly.
3. Lift the inner door plate assembly up, until the
mounting pins are out of the holes in the
pressure bar and set the assembly aside.
4. At this time, the bushings can be replaced if
necessary, by removing the bushings from the
pin on each block hinge.
5. Reverse procedure to install and check for
proper operation.
Page 20 of 88
VL SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
HEATER CONTACTORS
REGENERATED STEAM MODELS
(STEAM COIL)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Open the cabinet base doors, remove the two
screws from the contactor box cover and lift
cover off.
WARNING: SHUT OFF THE STEAM SUPPLY
BEFORE SERVICING THE UNIT.
2. Disconnect the electrical lead wires to the coil
and the power supply wires from the contactor
being replaced.
1. Disconnect pipe unions in the steam supply line
to the coils and in the condensate discharge
line from the coils.
3. Remove the screws form the base of the
contactor and lift out.
2. Remove header that supplies steam to the coils
by disconnecting union at each coil.
4. Reverse procedure to install and check for
proper operation.
3. Remove coil condensate collection header.
4. Remove bolts securing the coil being replaced
and pull coil forward.
HEATING ELEMENTS
5. Clean the mating surfaces of the steam coil
flange and the boiler.
6. Reverse procedure to install a new steam coil
and gasket.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
7. Check steamer for proper operation.
1. Open the cabinet base doors, remove the two
screws from the contactor box cover and lift
cover off.
2. Disconnect the electrical lead wires to the
element being replaced.
3. Remove the bolts securing the heating element
flange to the boiler and lift the element out.
4. Clean the mating surface of the boiler and
install a new flange gasket and heating
element.
5. Check for leaks and proper operation.
Page 21 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
SERVICE PROCEDURES AND ADJUSTMENTS
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRES ELECTRICAL TEST OR
MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL
TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST
EQUIPMENT AND REAPPLY POWER TO TEST.
NOTE: Boiler water capacities vary between seven
BOILER
to nine gallons for both gas and electric models
depending on the boiler size and BTU/KW rating.
Inspection
NOTE: If deliming solution accidently comes in
contact with steamer components, lightly rinse off
with clean water.
It is recommended the boiler be inspected for
excessive scale and lime build up on a quarterly
basis. In hard water areas or for steamers heavily
used, a more frequent interval should be used. This
inspection consists of an internal examination and
cleaning of the boiler, an examination of the two
hanging descalers, and for lime build up on the
water level probes. Also, a check of all boiler
controls, including the pressure switches.
A. Models with Blowdown Timer - Pour
deliming solution into boiler shell. Proceed
to step 9.
B. Models without Blowdown Timer - Turn off
the incoming water supply. Turn the power
switch ON to close the drain valve. Pour
deliming solution into boiler shell. Proceed
to step 9.
Periodic service must be performed as outlined in
these procedures. See “WATER CONDITIONING”
under “GENERAL”.
C. Models with Deliming Port Assembly -
Before pouring deliming solution into
boiler, clean the seating surfaces for the
hand hole gasket and then install a new
gasket. Position the hand hole plate and
tighten down. Turn off the incoming water
supply. Turn the power switch ON to close
the drain valve. Open the deliming
WARNING: READ AND FOLLOW THE
INSTRUCTIONS ON THE CLR BOTTLE. USE
PLASTIC OR RUBBER GLOVES TO AVOID SKIN
CONTACT. IF CLR LIQUID COMES IN CONTACT
WITH THE SKIN, RINSE WITH CLEAN WATER.
Clean-Out (All Boiler Models)
assembly valve and pour the deliming
solution into the port. Close the deliming
assembly valve and proceed to step 10.
1. Turn steamer OFF and drain boiler.
2. Remove hand hole plate and gasket (top front)
from the boiler by removing the nut and clamp,
then tapping the cover lightly to free it while
holding the cover stud. This prevents the cover
from dropping into boiler.
3. Remove old descaler retaining springs if
present.
4. With a wire brush, or equivalent, dislodge and
remove all loose scale from boiler shell. The
loose material must be either scooped from the
boiler or flushed through the drain.
5. Check probe canister and float valve assembly
(regenerated models) for a scale build up and
clean as necessary.
6. Check drain hole for obstructions.
7. Inspect the condition of the descalers as
outlined in this section and replace if
necessary.
9. Clean the seating surfaces for the hand hole
gasket and then Install a new gasket. Position
and tighten the hand hole plate.
8. Mix the deliming solution according to the
instructions for the chemical being used.
Page 22 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
10. Cooking compartment timers are to be in the
OFF position. Turn the boiler switch ON and
open water valve if necessary.
B. Models without Blowdown Timer - Turn
off the incoming water supply. Turn the
power switch ON to close the drain valve.
Open the deliming assembly valve and
pour the deliming solution into the port.
Close the deliming assembly valve and
proceed to step 3.
11. Boiler is to operate under pressure for 90
minutes or per the instructions for the chemical
in use.
12. Drain boiler by normal methods.
13. Refill boiler and allow to heat until fully
pressurized.
14. Repeat step 13 three times.
15. The steamer is now ready for normal operation.
Deliming Only (Models with Deliming Port
Assembly)
Boiler deliming should be performed on a weekly,
bi-weekly or monthly basis, depending on the quality
of the local water supply. See “WATER
CONDITIONING” under “GENERAL”.
On steamers using a water purification system,
follow the instructions for that system to delime the
boiler. Only use the type of chemical recommended
or described in the instructions for deliming with this
type of system.
3. Top compartments are to be in the OFF
position. Turn the boiler switch ON and open
water valve if necessary.
4. Boiler is to operate under pressure for 90
minutes or per the instructions for the chemical
in use.
1. Turn steamer OFF and drain boiler.
2. Mix the deliming solution according to the
instructions for the chemical being used.
5. Drain boiler by normal methods.
NOTE: Boiler water capacities vary between seven
to nine gallons for both gas and electric models
depending on the boiler size and BTU/KW rating.
6. Refill boiler and allow to heat until fully
pressurized.
7. Repeat step 6 three times.
8. Steamer is now ready for normal operation.
Descaler
NOTE: If deliming solution accidently comes in
contact with steamer components, lightly rinse off
with clean water.
The descaler is accessible through the hand hole
opening. It is a coiled wire wound around a solid
cylindrical core, and hangs by an open loop from the
shell's horizontal stay rod, about 4 inches from the
front of the shell. If the wire is eaten through, or if
the core of the descaler is eaten away to half its
original size, a new descaler should be installed.
A. Models with Blowdown Timer - Open
the deliming assembly valve and pour the
deliming solution into the port. Close the
deliming assembly valve and proceed to
step 3.
To install a new descaler, stretch its wire coil so the
descaler hangs with its core completely below the
minimum water level in the boiler, but hanging free.
The descaler must not contact the bottom of the
boiler shell, electric heating elements or
regenerating steam coils.
Page 23 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
5. Once the water level reaches the high level
WATER LEVEL CONTROL(S)
TEST
(HL) probe, the inverse latching relay of the
board (solid state) should energize and lock
through the low level probe (LL) and ILR-1
contacts. With ILR-2 contacts open, the HL
relay is de-energized and HL LED goes out.
With the HL-3 contacts open, the boiler fill
solenoid should de-energize and stop the boiler
fill.
Loose electrical connections may prevent the heat
from coming on or may cause the boiler to overfill.
An accumulation of lime scale on or near the water
level sensing probes may cause them to retain
water (moist) on the probe surface and give a false
reading. Also, a cracked or damaged insulator may
give a false reading. These conditions may prevent
the boiler from filling or cause dry firing. Dry firing
will result in damage to the heating elements on
electric models or to the boiler on gas or electric
models.
6. If water is in the boiler but is not being detected
by the water level probes, the probes may need
cleaned and/or boiler delimed. See “Water
Level Probes” as outlined below for inspecting
and cleaning of probes and “BOILER” for a
procedure on boiler inspection, clean-out and
deliming.
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
7. Turn the power switch OFF and disconnect the
lead wire from each probe. Check the probes
as outlined below.
A. With an ohmmeter, check between the
probe terminal and boiler shell. An open
circuit should be present when the boiler is
empty. If resistance is present, remove
and inspect the probes as outlined below
under “Water Level Probes”. When the
boiler is full of water, a resistance reading
should be measurable between the probes
and boiler.
Solid State - Low level Cut-Off & Differential
Control
1. Turn the power switch ON.
2. Ensure that water is filling the boiler.
A. Confirm that water supply valve(s) are
turned on.
B. Observe boiler water level in the water
level gauge. If empty, boiler should fill in
approximately 11 minutes.
NOTE: The actual resistance reading will depend on
water quality and probe condition.
3. Check the voltage across terminals L1 & L2 on
the board. Meter should read 120VAC.
8. After performing steps 1-5A and verifying the
water level control boards operation, if the
control is not functioning as described, then
replace it and check for proper operation.
A. If voltage is correct then the high level
(HL) relay should energize, closing HL-3
contacts and the HL LED should light up.
The boiler fill solenoid should then
Electro Mechanical - Low level Cut-Off &
Differential Control
energize and start filling the boiler. Verify
boiler fill solenoid valve is receiving
120VAC and water is flowing through it.
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
B. If boiler fill solenoid is receiving power but
no water is flowing, inspect fill solenoid for
malfunction or valve for clogged ports. If
solenoid is bad or ports can not be
1. Ensure that water is filling the boiler.
A. Confirm that water supply valve(s) are
turned on.
cleaned, then replace boiler fill solenoid
and check for proper operation.
B. Observe boiler water level in the water
level gauge.
C. If boiler fill solenoid is not receiving power
and the electrical connections have been
checked, then the HL relay is not being
energized or the HL-3 contacts are not
closing. Replace water level control board
and check for proper operation.
C. Verify boiler fill solenoid valve is receiving
120VAC and water is flowing through it.
2. Check for correct voltage being applied to the
low level and differential water level controls.
4. If boiler is filling properly, when the water level
reaches the low level cut-off (LLCO) probe,
LLCO relay should energize closing LLCO-2
contacts, heat source should come on
(standard models only) and LLCO LED will
light.
A. Turn the water supply valve off then turn
the power switch ON. Check the input
voltage across terminals 1 & 2. Meter
should read 120VAC. If voltage is correct
proceed to step 2B. If voltage is incorrect,
find the source of the problem and repeat
this step.
Page 24 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
B. With the boiler empty, check the voltage
2. If lime scale build up is evident on the probe,
thoroughly clean it removing all deposits from
the probe and insulator. Do not use any thing
abrasive on the insulator; use a soft cloth.
across terminals 9 & 10. Meter should
read 300 to 350VAC. If voltage is correct
proceed to step 3. If voltage reading is
approximately 30VAC then the internal
contactor is energized but the probes are
scaled over and moist and/or have a
damaged insulator giving a false reading.
See “Water Level Probes“ listed below for
inspecting and cleaning and “BOILER” for
procedures on boiler inspection, clean-out
and deliming. If you do not read any
voltage, then contactor coil on the water
level control is bad and the control should
be replaced. Check for proper operation
after replacement.
3. Inspect the probes for a cracked or damaged
insulator. If a probe appears to be damaged,
replace it with a new one and proceed to step
5. If a probe does not appear to be damaged
then proceed to step 4.
4. Check through the probe socket opening in the
top of the canister assembly for the presence of
water. Water must drain from the probe
canister and if in doubt, pour water into the
canister and observe that it drains quickly. If
water fails to drain from the canister, remove
the cover or canister assembly and clean.
3. If water is in the boiler but is not being detected
by the water level probes, the probes may need
cleaned and/or boiler delimed. See “Water
Level Probes“ listed below for inspecting and
cleaning and “BOILER” for procedures on
boiler inspection, clean-out and deliming.
5. Reverse procedure to install and check for
proper operation.
CYCLING AND HIGH LIMIT
PRESSURE SWITCHES
(GAS AND ELECTRIC MODELS)
4. Turn the power switch OFF and disconnect the
lead wire from each probe. Note the location of
the probes and the number of the wire
connected to it.
A. Check the resistance between the probe
terminal and boiler shell. An open circuit
should be present when the boiler is
empty. If resistance is present, remove
and inspect the probes as outlined below
under “Water Level Probes”. A resistance
reading should only be measurable
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
Remove the boiler control box cover as outlined
under “CYCLING AND HIGH LIMIT PRESSURE
SWITCHES (GAS AND ELECTRIC MODELS)” to
access the two controls. The pressure switch on the
right is the cycling or primary control; the one on the
left is the high limit control. They are identical
switches, differing only in their settings.
between the probes and boiler shell
(ground) when the boiler is full of water.
NOTE: The actual resistance reading will depend on
water quality and probe condition.
5. If after performing steps 1-4 and the control is
not functioning properly, verify the water level
controls operation as outlined in “WATER
LEVEL CONTROLS” under “ELECTRICAL
OPERATION”.
Turn the power ON and let the boiler come up to
pressure. Close and seal one of the compartment
doors, set a time past 5 minutes on the cooking
timer, pull the steam control arm handle forward and
turn the compartment power switch ON to exhaust
pressure from the boiler. Observe boiler pressure
gauge readings for several cycles and compare
them with the pressure settings in the chart.
6. After checking the above items, if the low level
cut off or differential water level control does
not appear to be functioning as described, then
replace the control and check for proper
operation.
If the readings differ, adjust the pressure settings as
described below.
Water Level Probes
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the cover over the water level probes
and disconnect the lead wire from each probe.
Note the location of each probe and the
number of the wire connected to it. Remove
each water level probe for examination.
Page 25 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
Two slotted and square headed adjustment screws
1. Remove the coil assembly from the valve stem
by lifting up on the retaining cap at the top of
the solenoid valve and sliding the metal cover
plate off.
extend through the top of the switch case. A
pressure scale and indicating pointers are visible
through the sight glass window to indicate the
approximate pressure setting. The adjustment screw
directly above the right side pointer changes the
cut-out (off) set point and the adjustment screw
directly above the left side pointer changes cut-in
(on) set point. Adjust the screw to obtain the proper
cut-out (off) setting first, then adjust the other screw
to obtain the proper cut-in (on) setting. Turn the
screw clockwise to increase the pressure setting and
counterclockwise to decrease the pressure setting.
The pressure settings for each switch are listed
below.
2. Clamp the body of the valve in a vise.
3. Mark a scribe line on the stem nut to the valve
body for proper retightening.
4. Remove the stem locking nut to remove the
stem from the valve body.
5. All parts are now accessible for inspection and
cleaning.
NOTE: If internal solenoid parts appear to be
damaged or worn, then replace the solenoid valve.
Do not reuse damaged or worn parts. No internal
solenoid parts are available as a service
replacement.
BOILER PRESSURE SETTINGS (PSI)
CYCLING
HIGH
LIMIT
CONTROL
TYPE
VL
MODELS
A. Check rubber seal on bottom of plunger.
B. Check plunger spring.
ON
OFF ON OFF
PS
AS
SS
MS
AS
SS
MS
C. Check O-ring in valve body.
D. Check ports in valve body.
With
Compartment
Pressure
9
11
6
2
15
15
Regulating Valve
With-Out
Compartment
Pressure
4
6
Regulating Valve
FILL AND COLD WATER
SOLENOID VALVES
6. Reverse procedure to install.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
COMPARTMENT PRESSURE
ADJUSTMENT
Check to assure the solenoid valve is receiving
power. If the solenoid valve is receiving power but
the valve is not opening, the coil may be
malfunctioning. Replace the solenoid valve and
check for proper operation. If the solenoid valve is
receiving power and the valve appears to be
opening but little or no water is flowing through it,
then the valve ports may be clogged with debris or a
valve component malfunctioning. To check solenoid
valve further, follow the procedure outlined below.
Remove the left side panel from the boiler base to
access the compartment pressure regulating valve.
If the steamer is equipped with the compartment
pressure regulating valve and the steamer is
operating, set the pressure regulating valve to read
6 psi on the compartment gauge. Turn the hex head
screw at the top clockwise to increase the pressure
and counterclockwise to decrease. If the steamer is
not equipped with the compartment pressure
regulating valve, then the compartment will cycle at
the same pressures of the boiler. A mechanical
pressure relief valve serves as a safety backup
control and is pre-set for a maximum of 8 psi.
Disassembly
NOTE: It is recommended that the valve be
removed for cleaning as outlined in this procedure.
This will prevent damage to the lines and fittings
when the stem is removed from the body.
Page 26 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
If water fails to drain from the canister, remove the
HIGH LIMIT THERMOSTAT
cover or canister assembly and clean. These
conditions indicate extremely poor water quality
being supplied to the boiler and/or boiler clean out
and deliming has not been performed.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
The water condition must be cleared up immediately
with a proper water conditioner to avoid further
problems with the steamer. Re-install the water level
probes and canister assembly (if applicable).
Perform a boiler inspection, clean-out and deliming
procedure as outlined under “BOILER”. Check for
proper operation.
Remove thermostat (bi-metallic disk type) as
outlined under “HIGH LIMIT THERMOSTAT” in
“REMOVAL AND REPLACEMENT OF PARTS”.
Inspect the temperature sensing side of thermostat
for corrosion or rust. Clean mounting and thermostat
surfaces before remounting or replacing. A good
metal-to-metal contact is essential for proper
functioning of the thermostat. This service must be
performed at least once a year. If thermostat mating
surface can not be throughly cleaned or is severely
pitted and rusted, then replace and check for proper
operation.
Water may be draining through an open boiler
blowdown solenoid valve as quickly as it’s fed to the
boiler. Loose wiring, a burned out coil or particles of
scale trapped in the valve seat may prevent the
valve from closing.
Newer steamer models use a plunger type rod that
raises and lowers to permit steam/water flow out of
boiler. If debris has accumulated around the water
orifice, the plunger may not seat properly to close
off the opening. If this symptom is suspect, remove
the solenoid as outlined in “FILL AND COLD
WATER SOLENOID VALVES”. Remove any debris
found on sealing surfaces, reassemble and install. If
the solenoid valve still does not function properly,
replace it with a new valve and check for proper
operation.
BOILER NOT FILLING WITH
WATER
Ensure that water to the steamer is turned on, then
turn power switch ON. After approximately 10
minutes, if no water is observed in the water level
gauge sight glass, then check for a problem with the
boiler fill solenoid valve, water level control(s) or the
water level probes. See “WATER LEVEL
CONTROL TEST”. Also, ”water hammering” in the
supply line, in conjunction with a check valve can
cause a high water pressure pocket in the water line
to the fill solenoid valve. The fill solenoid valve will
not be able to overcome this pressure and operate
to supply the boiler with water. Shut off the water
supply and relieve the pressure in the line. Turn the
water supply back on and check for proper
operation.
Older steamer models have a movable blade and
when closed, the blade reacts as a guillotine that
should be free to move fully down into the valve
pocket (projection at bottom of valve) so that the
pierced hole in the blade aligns perfectly with the
body opening. If debris has accumulated in the
bottom of the valve pocket, then the blade will not
move into the pocket completely. If this symptom is
suspect, remove the solenoid as outlined in “FILL
AND COLD WATER SOLENOID VALVES”.
NOTE: On this valve body, remove the two
assembly bolts holding the brass body together and
remove the loose internal parts. Remove any debris
found on sealing surfaces, reassemble and install. If
the solenoid valve still does not function properly,
replace it with a new valve and check for proper
operation.
NOTE: To eliminate this problem, the customer
must install a “water hammer suppression device” in
the supply line to the boiler.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
BOILER BLOWDOWN DRAIN
SOLENOID VALVE
Scalants may be covering the water level control
probe giving a false indication of a sufficient water
level in the boiler. Remove and thoroughly clean the
water level probes to remove scalants and lime
build up. Also, Check through the probe socket
opening in the top of the canister assembly for the
presence of water.
The water contained in the boiler, being under
pressure, should be blown through this valve and be
noticeably visible exhausting out the steamer drain.
Daily boiler blowdown is essential to proper
operation and component life by removing sediment
and scalants that may be lodged in the chamber of
the boiler.
Water must drain from the probe canister and if in
doubt, pour water into the canister and observe that
it drains quickly.
Page 27 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
If the blowdown operation appears to function
NORMAL OPERATING STEAMER PRESSURES (PSI)
sluggishly or not at all, considerable scalants may
be lodged in the drain pipe and/or the valve.
Disconnect the valve from the drain line and inspect
both the valve and the drain pipe fixed to the boiler.
If considerable scalants or lime build up is apparent,
then not only the valve, but also the boiler and water
level probes must be thoroughly cleaned. See “FILL
AND COLD WATER SOLENOID VALVES” for an
inspection and cleaning procedure of a solenoid
valve and "BOILER” for a procedure on boiler
inspection, clean out and deliming.
CYCLING
HIGH LIMIT
CONTROL
TYPE
VL
MODELS
ON
OFF ON OFF
PS
AS
SS
MS
With
Compartment
Pressure
9
11
6
15
Regulating Valve
AS
SS
MS
With-Out
Compartment
Pressure
4
6
2
15
1. If your steamer has an automatic blowdown
drain valve.
Regulating Valve
A. Newer Models
1. All Models (With Boiler)
1) Are equipped with normally open
solenoid valves that close when
energized by the main power switch.
When the main power switch is
turned off, the solenoid valve is de-
energized and the boiler blowdown
valve re-opens.
A. Check for low water pressure input, line
strainer clogged or fill solenoid valve
malfunction. See “FILL AND COLD
WATER SOLENOID VALVES”.
B. Boiler blowdown solenoid valve may be
clogged and not fully closing. Check for a
slow leak out of steamer drain. If not able
to verify, then proceed to step 1C. If
blowdown solenoid valve appears to be
functioning properly, then proceed to step
1D.
B. Older Models
1) Turn the power switch(s) OFF and
press the blowdown timer button. This
activates the boiler blowdown timer
and energizes (opens) the solenoid
valve. Timer operates approximately
four minutes then shuts off.
C. Turn power switch OFF, disconnect lead
wires from blowdown solenoid and remove
it for inspection.
D. A heavy build-up of scalants has possibly
coated the interior of the boiler. The
2. If your steamer has a manual blowdown drain
valve.
insulating effect of the scalants hampers
heat transfer. Unbolt and remove the hand
hole cover plate and gasket assembly.
Examine interior of boiler and if scalants
and/or lime build up is apparent, perform a
boiler inspection, clean-out and deliming
procedure. See “BOILER”. If considerable
scalants are evident, then both the boiler
blowdown solenoid valve and the water
level probes must also be examined.
A. Turn the power switch(s) OFF then open
the valve to blowdown the boiler. Close
the valve at the end of the blowdown
sequence so boiler will be ready to fill.
BOILER SLOW TO PRESSURIZE
2. Gas Models
A. Low incoming gas pressure causes
reduced BTU output. Check incoming line
and manifold gas pressures as outlined in
“GAS MANIFOLD PRESSURE
If the boiler requires more than 15 minutes (20
minutes for regenerated models) to achieve normal
operating pressure as listed in below, then check the
following conditions.
ADJUSTMENT.”
B. Gas combination control valve
malfunction. Check incoming and manifold
gas pressures as outlined in “GAS
MANIFOLD PRESSURE ADJUSTMENT.”
If pressure adjustments are made and
manifold pressure remains low, replace
the combination valve and check for
proper operation.
Page 28 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
C. Gas burner ports clogged or obstruction
INLET WATER STRAINER
around air shutter. After a period of time,
gas burners can accumulate carbon in
their ports or become clogged by food and
grease debris from kitchen cleaning,
restricting performance. To clean burners,
remove them from burner box and boil in
water for 10 -15 minutes to dislodge clog.
Clean-out any remaining debris from the
gas ports using a wire brush, scribe or pic
type metal instrument. Remove any other
foreign objects that appear to be
The in-line Y strainer should be located upstream of
the fill valve solenoid. Shut off the water supply.
Unscrew the cap from the body on the leg of the Y
that should be pointing downwards toward the floor.
Remove the screen and any foreign particles
trapped in the opening. Rinse the screen thoroughly
to remove accumulated debris and replace the
screen in the valve body. If screen can not be
thoroughly cleaned, replace it with a new one.
Reinstall the cap and ensure that the Y strainer is
positioned with the cap pointing downward to catch
debris.
obstructing the gas ports or air shutters.
D. Gas orifice clogged or obstructed around
air shutter. It is possible for debris to
become lodged in the small gas orifice
opening over time. Clean-out the gas
orifice using a round metal instrument of
the same hole diameter or slightly smaller.
Clean as needed. If clogging reappears,
the orifice should be removed, cleaned
and reinstalled. Remove any other foreign
objects that appear to be obstructing the
gas orifice or air shutters.
The pressure regulating valve strainer will become
clogged if dirty steam lines are connected to direct
steam models. Remove the hex nut on the bottom
of the pressure regulating valve to clean the strainer
and valve seat.
PILOT AND THERMOCOUPLE
ASSEMBLY (GAS MODELS)
3. Electric Models
A. One or more electric heating elements
malfunctioning. See “HEATING
ELEMENTS”
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
B. One or more heater contactors not pulling
in to power heating elements.
C. If steamer operates under three phase
power, then check line for all phases.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
D. Heavy scale build up on heating element
causes reduced heating.
The pilot thermocouple when heated, supplies a DC
millivolt signal to an internal solenoid valve on the
gas combination control valve. This solenoid valve
is designed to shut off the gas flow to the pilot and
main burners in case of a malfunction in the system.
When energized by the thermocouple voltage, the
valve is held in the open position to permit gas flow.
The pilot burner flame is controlled by an adjustable
needle valve located under a small cap screw on
the combination control valve.
4. Direct Steam Models
A. Building steam supply pressure low.
B. Cooking compartment steam solenoid
valve malfunction.
C. Steam pressure regulator adjusted too
low.
D. Clogging in the steam line reduces steam
supply.
When experiencing pilot outages, visually check
pilot flame for the proper contact on thermocouple
and the flame color. Also, check to see that
excessive air drafts are not interfering with proper
heating of the thermocouple by the pilot flame.
5. Regenerated (Steam Coil) Steamers
A. Heavy scale build up inside copper steam
coil.
B. Building steam supply pressure low
The pilot flame should be a steady blue flame that
envelopes the thermocouple tip. The flame should
be about one inch long with half its length extending
beyond the outer edges of the pilot shield. If the pilot
flame does not appear to be this length and color,
then adjust as necessary. See the diagram below for
an example of unsatisfactory pilot flames. Turn
clockwise to decrease pilot flame and
C. Cooking compartment steam solenoid
valve malfunction.
counterclockwise to increase.
Page 29 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
Check the thermocouple output voltage as follows:
NOTE: If adjustments in gas or pilot pressure
settings are made, always replace the adjustment
cover screw to assure proper gas control operation.
1. Turn the power switch OFF and disconnect the
thermocouple from the gas combination control
valve.
2. Check the thermocouple DC millivolt output
with a VOM. If a meter is not available, replace
the thermocouple with a new one and check
operation again.
A. Install a thermocouple adaptor into the
connection on the gas combination control
valve. Screw the thermocouple in to the
adaptor then connect the meter leads to it.
See “TOOLS” under “GENERAL” for
information on thermocouple adaptor. If a
thermocouple adaptor is not available then
turn the power switch OFF, disconnect the
thermocouple from the gas combination
control valve and proceed to step 2D.
B. Turn the power switch ON and light the
pilot. Allow the pilot to heat the
thermocouple for one to two minutes and
take a closed circuit reading. Compare the
readings with the chart below.
1) If the reading is less than the
minimum or thermocouple is not
operating as described, replace the
thermocouple as outlined under
“PILOT AND THERMOCOUPLE
ASSEMBLY (GAS MODELS)” in
“REMOVAL AND REPLACEMENT
OF PARTS” then check for proper
operation.
If the adjustment does not result in a pilot flame of
proper size, then gas might not be flowing properly
to the pilot. Check for a plugged pilot orifice, a
kinked or plugged pilot gas supply tube and for low
gas supply pressure. The pilot operates unregulated
at gas supply pressures while the pressure regulator
in the combination control valve regulates pressure
to the main burners only. Visually check the
thermocouple tip (hot end) and tube lead for kinks or
pinches that might be causing a short between the
tube and the wire inside. Also, check the threaded
connector tip for corrosion, tarnish or dirt which can
cause a poor connection. If the thermocouple shows
either of these signs, it should be replaced with a
new one.
2) If the reading is within the range listed
in the chart below then thermocouple
is operating properly. Reconnect the
thermocouple to the gas combination
control valve.
3) If after replacing thermocouple, the
pilot or main burners are still not
functioning properly, then a problem
in the gas combination control valve
exists as well. Replace the
combination control valve as outlined
under “GAS COMBINATION
CONTROL VALVE” in “REMOVAL
AND REPLACEMENT OF PARTS”
then check for proper operation.
NOTE: The connection of the tubing from the
thermocouple tip to the control valve is an electrical
connection and must be clean. Do not use any
sealing compound on the threads or over tighten the
threaded connection. Finger tighten the nut plus 1/4
turn with a wrench. Over tightening the nut could
crush the insulator, shorting the thermocouple.
C. Turn the power switch OFF and
disconnect the thermocouple adaptor from
the gas combination control valve and
thermocouple.
If the pilot flame is correct and there are no drafts,
then the problem is in the thermocouple output
voltage or the gas solenoid valve in the combination
control.
Page 30 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
D. With the thermocouple disconnected, 3. Loosen the set screw on the burner being
connect the meter leads to the tube and
threaded end. Turn the power switch ON
and light the pilot. Hold down the
adjusted. Closing the air shutter will decrease
primary air to the burner and opening the
shutter will increase primary air the burner.
OFF/PILOT/ON knob and allow the pilot to
heat the thermocouple for one to two
minutes. Take an open circuit reading and
compare with the chart below.
4. Monitor the burner flame and set the air shutter
opening as follows:
A. Open up the air shutter until the inner
portion (blue) of the flame lifts off the
burner port and then turn the air shutter
back until the flame touches the burner
port again. A slight tinge of orange and
yellow in the flame is acceptable. An
extremely yellow flame indicates too little
primary air (oxygen), producing poor
burning characteristics and the heating
efficiency drops off. A by product of this
would be soot (carbon).
1) If the reading is less than the
minimum or thermocouple is not
operating as described, replace the
thermocouple as outlined under
“PILOT AND THERMOCOUPLE
ASSEMBLY (GAS MODELS)” in
“REMOVAL AND REPLACEMENT
OF PARTS” then check for proper
operation.
3. If after checking and/or replacing
Factory air shutter settings are: natural
gas - open approximately ½ inch;
propane gas - fully open.
thermocouple, the pilot or main burners are still
not functioning properly, then a problem in the
gas combination control valve exists as well.
Replace the combination control valve as
outlined under “GAS COMBINATION
CONTROL VALVE” in “REMOVAL AND
REPLACEMENT OF PARTS” then check for
proper operation.
5. After the air shutter adjustment is made, tighten
the set screw.
Inspection
Remove gas burners by lifting burner up and sliding
it to the rear just enough to clear the gas orifice
hood. Lower the front end of burner and bring it
forward under the gas manifold pipe. Inspect burner
for clogged or damaged ports. Clean or replace as
necessary. When reinstalling burners, assure that
locating pin is in the hole for proper positioning and
to prevent burner from rolling over.
NOTE: Gas combination control valves are not
serviceable and should not be disassembled. Once
you have isolated the problem to this control,
replace it. Do not attempt to repair the assembly.
THERMOCOUPLE
DC MILLIVOLT
READINGS
CLOSED CIRCUIT
(CONNECTED)
OPEN CIRCUIT
(DISCONNECTED)
AUTOMATIC IGNITION SYSTEMS
(GAS MODELS)
Typical
Range
15
10 - 20
20 - 35
When the main power switch is turned ON and the
ignition control modules reset switch is in the ON
position, the ignition control module is energized
with 24VAC between terminals five and six.
GAS BURNERS
High voltage is sent from terminal nine to the spark
electrode and an output of 24 volts is sent from
terminals two and three to the pilot coil in the
combination valve, allowing gas to flow to the pilot.
The sparking will continue for 90 seconds or until
the flame sensor has confirmed that an adequate
pilot flame is present.
The main gas burners are located under the boiler
for heating and number five to seven depending on
the steamer model. They are made of aluminized
steel with lanced type ports and have adjustable air
shutters in the front. Fixed orifice type hoods extend
from the manifold to establish gas flow to each
burner.
Air Shutter Adjustment
1. Ignite the burners and allow to heat up for at
least five minutes.
2. Verify the manifold pressure as outlined under
“GAS MANIFOLD PRESSURE
ADJUSTMENT”.
Page 31 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
Once the pilot flame is confirmed, a 24 volt output
A. Check to ensure that all electrical terminal
connections on the ignition control module
and the ignitor are clean and tight. If loose
connections are found, make the
from terminal one will be sent, allowing the main
valve (cycling) coil of the combination valve to
operate at the request of the cycling pressure
switch.
necessary adjustments.
B. Verify that the ignition control module and
the ignitor have good ground wire
connections. The ignitor mounting bracket
should have good metal to metal contact
to its mounting surface.
C. Remove the pilot ignitor and check the
following:
1) The gap between the spark probe and
the ground clip should be
approximately 1/8 inch. If the gap
appears to be excessive or poor
sparking is occurring then adjust.
Terminals:
1. Main Valve - 24VAC will be present on terminal
#1 with the pilot sensing electrode sensing an
adequate pilot fame. This output will remain
present as long as the pilot flame remains
adequate.
2) Inspect the ceramic flame rod
insulator for cracks or evidence of
exposure to extreme heat, which can
permit leakage to ground. If either of
these conditions exist, then replace
the pilot ignitor and re-test.
2. Common (MV/PV).
3. Pilot Valve - 24VAC will be present on terminal
#3 at the instant an input voltage is supplied to
the module. This voltage will remain present on
terminal #3 providing an adequate pilot flame is
established within 90 seconds. In the event that
an adequate pilot flame is not established
within 90 seconds this output voltage will drop
out.
3) Check the ignition cable for tightness
or damaged insulation. If the ignition
cable appears to be damaged, then
replace it and re-test.
4. Ground (burner).
5. 24VAC Neutral (ground).
6. 24VAC Input.
2. Install the pilot ignitor and attach ignition cable.
A. Turn the main power switch ON and verify
the ignition control modules re-set switch
is ON. Observe spark condition from
ignitor.
7. High Voltage to spark electrode (The pilot
flame current is sensed by the Ignitor Module
via the spark electrode high voltage wire and
terminal #9).
1) If a spark from ignitor is present and
ignites the gas from the pilot and
burner then the system is working
properly.
Spark Ignition Control Test
1. If the ignition control module does not appear
to be sparking to ignite gas, perform the
following:
Page 32 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
2) If a spark from ignitor is present but
does not ignite gas before the ignition
control module locks out, (90 sec.)
there may not be enough gas in the
line for ignition. Verify the gas supply
and gas combination control valve
are both on. Turn the ignition control
modules re-set switch OFF then ON
to reset the module. Sparking should
then resume to ignite gas. The
4. After the burner lights, compare the manometer
pressure reading to the pressure chart near the
end of this procedure.
A. If other appliances are connected to the
same gas line, turn them all ON and check
manometer pressure reading again. If the
pressure drops ½ inch water column or
more, then the incoming pressure should
be checked. then the gas supply needs to
be checked by the gas line installer or the
local gas company for adequate sizing.
module may need reset several times
before ignition takes place.
B. If no other gas appliances are connected
to the gas line or the pressure does not
drop as described above but the manifold
pressure still requires adjustment, proceed
to step 5.
3) If ignitor is still not sparking proceed
to step 3.
3. Check the ignition control module and
transformer.
A. Turn the ignition control modules re-set
switch OFF then ON to eliminate a lockout
condition.
5. Remove the adjustment screw cap to access
the pressure adjustment screw.
B. Check for 24VAC output on the ignition
control module transformer.
1) If 24VAC is present between
terminals 5 & 6 on the ignition control
module but ignitor is not sparking,
then replace ignition control module
and re-test.
2) If 24VAC is not present then ensure
that transformer is receiving 120VAC
input. If ignition control module
transformer is receiving proper
voltage, then replace ignition control
module transformer and re-test.
4. After making the necessary component
adjustments or replacements, check for proper
operation.
6. After the burner lights, set the pressure as
outlined below.
GAS MANIFOLD PRESSURE
ADJUSTMENT
A. To increase pressure, turn the screw
clockwise.
B. To decrease pressure, turn the screw
counterclockwise.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
NOTE: Accurate gas pressure adjustments can only
be made with the gas ON and the burner lit.
PRESSURE READINGS
(INCHES W.C.)
WARNING: SHUT OFF THE GAS SUPPLY
BEFORE SERVICING THE UNIT.
LINE
GAS TYPE MANIFOLD
1. Open the front cabinet doors and turn the gas
combination control valve off.
RECOMMENDED
MIN
MAX
Natural
4.0
7.0
5.0
2. To measure the manifold pressure, remove the
1/8 inch NPT plug (pressure tap) on the outlet
side of the valve and attach a manometer.
14
Propane
10.0
11.0
11.0
3. Turn the gas combination control valve and the
main power switch to ON.
NOTE: If the incoming line pressure is less than the
minimum stated, then the manifold pressure can not
be set correctly.
Page 33 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
7. Once the correct pressure has been set, turn
HEATER CONTACTORS
the power switch OFF, replace the adjustment
screw cap and 1/8 inch NPT plug (pressure tap)
on the outlet side of the valve.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
8. Check for proper operation.
DIRECT STEAM MODELS
The contactor can be serviced by removing the
cover of the contactor box.
These models consist of a pressure regulator and
gauge that run off a buildings potable steam supply.
The regulator used will be of the adjustable type and
should be set for a discharge pressure of 10 psi. The
maximum input pressure to the regulator should be
15 psi. Incoming power (120VAC) for the
A noisy contactor (hum or chatter) is generally due
to excessive dust or dirt on the armature pole faces
or around the armature core preventing the magnet
coil from pulling the armature into a completely
sealed position. This can usually be corrected by
blowing or wiping the pole faces clean. To inspect
electrical contacts, remove cover at top of contactor
by removing two screws which hold it in place.
Replace contactor if the electrical contacts appear
to be severely pitted or burned.
compartment controls is supplied from a junction
box in the base.
REGENERATED STEAM
(OLDER MODELS)
HEATING ELEMENTS
The steam coils on a regenerated type steamer are
intended for use at a steam supply pressure of 15
psi maximum. A pressure regulating valve is
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
available as optional equipment for steamers where
a buildings steam supply pressure exceeds 15 psi.
The regulator used will be of the adjustable type and
should be set for a discharge pressure high enough
for good steam generation. This pressure can be
monitored by the supplied pressure gauge. The
regulator should be set, only when steam is flowing
(steam solenoid valve is open). If steam is heavy
with condensate, install a ball float trap in the steam
line before the pressure regulating valve.
1. Measure the voltage at the heating element
terminals and verify it against the data plate
voltage.
A. If voltage is incorrect, find the source of
the problem.
B. If voltage is correct, check current draw
(amps) through the heating element lead
wires. See table below for proper
values.
WARNING: SHUT OFF THE STEAM SUPPLY
BEFORE SERVICING THE UNIT.
To remove a steam coil, disconnect union in steam
supply line to the coils and in the condensate
discharge line from the coils. Remove header that
supplies steam to coils by disconnecting union at
each coil. In same way, remove coil condensate
collection header. Remove four bolts clamping each
coil flange in place and pull coil forward. Use a new
flange gasket when replacing coil. The faces that
mate with gasket must be clean.
C. If current draw is correct then heating
element is ok.
D. If current draw is not correct then replace
the element and proceed to step 3.
NOTE: When replacing an element, always use a
new gasket and ensure that the flange and tube
surfaces which contact the gasket are clean. If
removed element shows a pronounced scale
build-up on its heating tubes, the other elements
should be removed and mechanically cleaned to
remove the scale. This will prolong their life. DO
NOT immerse elements in a chemical solution to
descale.
Turn steamer power switch ON, allowing steam
generation and, consequently, pressure to rise to
normal operating level and then turn power switch
OFF for a final purging of boiler and steam supply
lines. Steamer is now ready for use.
2. Check for proper operation.
Page 34 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
AMPERAGE
PER LINE
RESISTANCE
PER
ELEMENT
(OHMS)
NUMBER
OF
ELEMENTS ELEMENT
KW
PER
TOTAL
KW
VOLTAGE
1 PH 3 PH
208
240
480
18
18
18
2
2
2
9
9
9
87
75
50
44
22
14.42
19.20
76.80
*220/380
240/415
18
2
9
25
19.20
208
240
480
24
24
24
2
2
2
12
12
12
116
100
68
58
29
10.82
14.40
57.60
*220/380
240/415
24
2
12
34
14.40
208
240
480
36
36
36
4
4
4
9
9
9
100
87
14.42
19.20
76.80
44
*220/380
240/415
36
4
9
50
19.20
208
240
480
42
48
48
4
4
4
10.5
12
117
116
58
12.36
14.40
57.60
12
*220/380
240/415
48
4
12
67
14.40
NOTES:
1. Values in the table are nominal. Tolerance is +/-10 %.
2. Asterisk (*) indicates 3 phase/4wire.
3. Each heater has three internal elements.
Page 35 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
D. If the cooking cycle is started normally, but
THERMAL SWITCH - PREVENT
AND AUTOMATIC MODELS
the red light and timer do not come on or
an abnormal amount of time elapses
before they come on, then the load
compensator is set too high. Also, if the
timer stops, the red light goes out, and the
buzzer does not sound after the
compartment has exhausted the steam or
if the time is set as usual for the product
and the product is overcooked or if the
time is set as usual for the product and the
product is overcooked.
The load compensator is a thermal switch in a
stainless steel housing that screws into a 3/8 NPT
fitting (newer models) on the left side wall of the
compartment. The switch contacts should close
when the compartment temperature reaches 180 F,
supplying power to the steam exhaust solenoid
valve, pilot light and cooking timer motor.
1. Newer Models
E. If there is too short a time between starting
and the red light coming on, or if it comes
on immediately, the load compensator is
set too low. Also, if the time is set as usual
for the product and the product is
undercooked.
A. This switch is NON-ADJUSTABLE. Check
to see if the switch is operating properly as
described below. If the switch is suspected
to be malfunctioning, replace it and check
for proper operation.
2. Older Models
A. The switch can be adjusted by turning the
slotted screw. Turn the screw clockwise to
lower the closing temperature and
counterclockwise to raise the closing
temperature. Check the operation of the
switch as described below. These models
are ½ NPT.
WATER LEVEL GAUGE
ASSEMBLY
1. Close the valve at the top and at the bottom of
the gauge assembly.
2. Unscrew the packing nuts at the top and bottom
of the glass tube.
The correct adjustment or verification of the load
compensator can best be made by using a digital
thermometer and thermocouple to sense the
compartment temperature.
3. Slide the glass tube upwards, until the bottom
of the tube is clear of the fitting and lift it out.
1. Position the thermocouple near the exposed
bulb of the load compensator inside the
compartment.
4. Reinstall the tube and use new sealing
washers. Do not over tighten the packing nuts,
it could break the gauge glass.
2. Close and seal the compartment. Pull the
steam control arm handle forward, set the timer
and turn the compartment power switch ON.
5. Open the top and bottom valves fully.
6. Check for proper operation.
3. Monitor the thermocouple temperature, and
adjust or verify (as applicable) the load
compensator temperature.
A. The red light of the compartment switch
should light when the thermocouple reads
185 ±7 F.
B. After the cooking cycle ends and the
compartment temperature lowers, the
thermal switch should then re-open at
165 ±7 °F.
C. If the load compensator can not be
adjusted correctly or the temperature is
out side the allowable limits, then replace
thermal switch and check for proper
operation.
Page 36 of 88
VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
Replace the packing nut and control arm bracket.
STEAM GATE VALVE(S)
Tighten the packing nut finger tight plus ½ turn and
check for proper operation. If steam continues to
leak, tighten the packing nut in additional ½ turn
increments until it stops and re-check operation of
the steam control arm.
On all models, each cooking compartment has its
own mechanical steam gate valve that supplies
steam to the cooking compartment when the steam
control arm handle is pulled forward. The Prevent
models use a solenoid valve to exhaust steam from
the compartment whereas the Automatic, Standard
and Manual models use an additional steam gate
valve to exhaust steam when the steam control arm
handle is returned to the rear. These gate valves are
a standard type and can be disassembled for
cleaning and gasket replacement.
NOTE: Do not over tighten packing glands, the
linkage system must be free enough for the spring
to return the steam control arm to the fully closed
position.
For other service to these valves, remove the stem
assembly and cap at the top of the valve. Check the
valve linkage for loose or binding parts.
The steam gate valve linkage for these controls are
simple and there function easily seen. The inlet and
exhaust steam gate valves must be positioned so
the inlet valve is open and the exhaust valve closed
when the steam control arm handle is pulled forward
and reverses when the control arm is released.
If steam leaks are noticed around the packing nut
and stem during cooking, tighten the packing nut
until the steam leak ceases. Release steam control
arm to ensure its automatic return. If arm does not
return freely or steam is still leaking, then further
inspection or adjustments are necessary. Turn the
timer and compartment power switch OFF and
blowdown the boiler. Remove the control arm
bracket and packing nut from the stem and clean
out the old string packing. The valve stems may
then be re-packed using a string packing suitable for
steam service.
NOTE: In the event of an electrical component or a
power failure, the steam control arm can be
operated manually on automatic models.
Page 37 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
ELECTRICAL OPERATION
When the water level drops below the low level (LL)
WATER LEVEL CONTROLS
probe, power is removed from the inverse latching
relay, the HL relay energizes through ILR-2 and HL
contacts change state. The fill solenoid is energized
through HL-3 to refill the boiler and the HL LED is lit.
The HL relay and LED will toggle ON and OFF
during a cooking cycle as needed.
Solid State - Low level Cut-Off & Differential
Control
The steamer is equipped with three water level
sensing probes (high, low and low level cut-off) and
a single water level control board. The water level
control board performs two functions:
1. Provide low level cut-off protection to shut off
the heat source in case the water level drops
below the low level cut-off (LLCO) probe.
2. Performs as a differential level control to
maintain the water level between the low and
high water level probes.
The water level control (WLC) has input voltage
(120VAC) across terminals 11 and 12 which powers
the transformer. On one side of the transformer
secondary, power is provided to the control by a
series path through chassis ground (terminal 10).
The other side of the transformer secondary
(12VAC) supplies power to one side of the internal
relays LLCO, HL and ILR. As water enters the
boiler, it becomes part of the water level control’s
circuit. When the water level in the boiler reaches a
probe, that circuit is completed.
The inverse latching relay of the board is de-
energized, leaving the ILR-1 (N.O.) and ILR-2 (N.C.)
contacts in their shelf state.
When the main power switch is turned ON, power is
supplied to the WLC board which energizes the high
level (HL) relay and illuminates the HL relay LED.
With the HL-3 contacts closed, the boiler fill
solenoid is energized and water begins filling the
boiler.
When the water level reaches the low level cut-off
(LLCO) probe, the LLCO relay is energized and
illuminates the LLCO LED. With the LLCO-2
contacts closed the heat source is then energized.
The LLCO relay will remain energized and its LED
will stay lit until the water level in the boiler drops
below the LLCO probe.
When the water level reaches the low level (LL)
probe, power to terminal 2 on the WLC board is
present but no switching occurs.
After the water level reaches the high level (HL)
probe, the inverse latching relay of the board is
energized and locked through the low level probe
(LL) and ILR-1 contacts. With ILR-2 contacts open,
this de-energizes the HL relay and the HL LED goes
out. With the HL-3 contacts open, the boiler fill
solenoid is de-energized, stopping the flow of water
into the boiler.
Page 38 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
When the boiler stops filling, press the manual reset
Solid State - Auxiliary Low Level Cut-Off
button on the boiler control box. On CSD-1 models,
this energizes the low water relay, turns off the low
water light and energizes the heat source auxiliary
control. On Cal-Code models, this closes and locks
the manual reset switch contacts to energize the
heat source auxiliary control.
This control serves as a safety backup to the main
water level control (WLC) board to meet Cal-Code
and CSD-1 code requirements. The auxiliary control
provides auxiliary low level cut-off protection to shut
off the heat source in case the water level drops
below the low level cut-off (LLCO) probe. A single
LLCO probe is connected to the auxiliary control.
The auxiliary water level control (WLC) has input
voltage (120VAC) across terminals L1 and L2 to
power the transformer primary. On one side of the
transformer secondary, power is provided to the
control by a series path through chassis ground. The
other side of the transformer secondary (12VAC)
supplies power to one side of the internal relay
LLCO. As water enters the boiler, it becomes part of
the auxiliary water level control’s circuit. When the
water level in the boiler reaches the LLCO probe,
the circuit is completed.
When the main power switch is turned ON, power is
supplied to the auxiliary WLC board but no
switching occurs. On CSD-1 models, the low water
level indicator light (amber) on the boiler control box
comes on.
When the water level reaches the low level cut-off
(LLCO) probe, the LLCO relay is energized and
illuminates the LLCO LED. With the LLCO-2
contacts closed the auxiliary heating control is then
energized. The LLCO relay will remain energized
and its LED will stay lit until the water level in the
boiler drops below the LLCO probe.
Page 39 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
When the water level reaches the low level cut-off
Electro Mechanical - Low level Cut-Off &
Differential Control
(LLCO) probe, the internal contactor coil on the low
water level control is energized. With the contacts
on terminals 7 & 8 now closed, the heat source is
then energized. The internal contactor coil will
remain energized until the water level in the boiler
drops below the LLCO probe.
The steamer is equipped with three water level
sensing probes (high, low and low level cut-off), a
differential level control (1G1GO) and a low level
cut-off control (1D1DO). The low-level cut-off is an
additional control that is identical to the differential
level control but serves as the safety backup to shut
off the heat source in case the water level drops
below the low level cut-off (LLCO) probe. The
differential level control maintains the water level
between the low and high water level probes.
When the water level reaches the low level (LL)
probe, power to terminal 7 on the differential level
control will be present but no switching occurs.
After the water level reaches the high level (HL)
probe, the differential control contactor coil is
energized and the normally closed contacts on
terminals 3 & 4 open, which de-energizes the boiler
fill solenoid and stops the flow of water into the
boiler. The internal contactor coil will have a locking
path through contacts 7 & 8 to the low level probe to
keep the coil energized after the water level drops
below the high level probe.
Each control is powered by input voltage (120VAC)
on terminals 1 and 2 which also connect to the
primary side of the internal transformer. The
transformer secondary (300VAC) will provide power
to the internal contactor coil through a series path
going from one side of the secondary winding,
through the contactor coil, through the water level
control probe, through the water in the boiler and to
the boiler for ground. The other side of the
When the water level drops below the low level (LL)
probe, the internal contactor coil is de-energized,
returning contacts 3 & 4 back to their normally
closed state and energizing the boiler fill solenoid to
refill the boiler. The water level must then fill to the
high level probe again, to energize the internal
contactor coil. The differential control will toggle ON
and OFF during a cooking cycle as needed.
transformer secondary is attached to ground.
When the main power switch is turned ON, both
water level controls are energized. The boiler fill
solenoid is then energized through the normally
closed contacts (terminals 3 & 4) on the differential
level control and water begins filling the boiler.
Page 40 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
Electro Mechanical - Auxiliary Low Level Cut-Off
This control serves as a safety backup to the main low level cut-off (LLCO) control to meet Cal-Code
requirements. The operation of the auxiliary control is identical to the main low level cut-off control but performs
a single function: 1) Provide auxiliary low level cut-off protection to shut off the heat source in case the water
level drops below the low level cut-off (LLCO) probe. A single LLCO probe identical to the LLCO probe on the
main low level cut-off control is connected to the auxiliary control.
The auxiliary control is powered by input voltage (120VAC) on terminals 1 and 2 which also connect to the
primary side of the internal transformer. The transformer secondary winding (300 VAC) will provide power to the
internal contactor coil through a series path going from one side of the secondary winding, through the contactor
coil, through the water level control probe, through the water in the boiler and to the boiler for ground. The other
side of the transformer secondary is attached to ground.
When the main power switch is turned ON, the auxiliary low level control is energized but no switching occurs.
When the water level reaches the low level cut-off (LLCO) probe, the internal contactor coil on the low level
control is energized, closing the contacts on terminals 7 & 8. The internal contactor coil will remain energized
until the water level in the boiler drops below the LLCO probe.
When the boiler stops filling, press the manual reset button on the boiler control box. This closes and locks the
manual reset switch contacts to energize the heat source auxiliary control.
Page 41 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
NOTE: The high pressure indicator light will remain
SEQUENCE OF OPERATION
on and the safety circuit de-energized until boiler
steam pressure is within operational limits (high limit
pressure switch closed) and the manual reset button
is pressed. The low water indicator light will remain
on and the safety circuit de-energized until the water
level in the boiler reaches the low level cut-off
probes (minimum level) for the water level control,
the auxiliary low level cut-off control and the manual
reset switch is pressed. The gas burners will not
light until these conditions are satisfied.
GAS MODELS
This sequence of operation is written for steamers
with electronic ignition, solid state water level
controls, CSD-1 (code) boiler controls option and
with Prevent cooking compartment controls. Refer
to schematic diagram numbers 3928 and 3929 for a
boiler control schematic and 3962 for a schematic
and wiring diagram on Prevent cooking
D. Water level control (WLC) is powered.
compartment controls.
Initial Fill and Preheat
1) High level (HL) relay is energized,
HL-3 (N.O.) contacts close and HL
LED lights up.
1. Conditions.
A. Power switch OFF.
2) The inverse latching relay of the
board remains de-energized, leaving
the ILR-1 (N.O.) and ILR-2 (N.C.)
contacts in their shelf state.
B. Ignition module reset switch ON
C. Cooking timers off.
D. Compartment power switches OFF.
E. Unit connected to correct voltage .
E. Auxiliary low water level cut-off control is
powered, LLCO-2 (N.O.) contacts remain
open.
1) L1 (HOT) to one side of the cooking
compartment controls; to one side of
the cold water condenser thermostat;
to one side of the power ON/OFF
switch.
F. With the HL-3 and ILR-2 contacts closed,
the fill solenoid is energized and water
boiler begins filling.
G. Blowdown solenoid valve is energized and
closes.
2) L2 (NEUTRAL) to one side of the
cooking compartment controls; to one
side of the cold water condenser
(CWC) solenoid valve; to one side of
the power ON/OFF switch.
H. Ignition module begins sparking to light
pilot after a 3 second delay.
1) If pilot ignition is established (pilot lit)
then a micro amp flame sense
F. Unit properly grounded. (Boiler and water
level control share a common ground)
current is sent back to the ignition
control module through the ignition
cable. Sparking stops, pilot remains
lit and is ready to ignite burners.
G. Water supply valve on.
H. Gas supply valve on.
I.
Gas combination control valve ON.
2) If pilot ignition is not established after
90 seconds, sparking stops and the
ignition control module locks out
power to the combination gas valve
(pilot valve and main valve remain
closed). The module remains locked
out until the reset switch on the
ignition control module box is
J. Control (cycling) pressure switch closed.
K. High limit pressure switch closed.
L. Cold water condenser (CWC) thermostat
open.
M. Blowdown solenoid valve (drain) open and
boiler empty.
switched to OFF then ON to re-start
the ignition trial cycle.
N. Compartment doors open.
2. Power switch turned ON. (located on boiler
control box)
NOTE: If the modules re-set switch is in the OFF
position, no sparking will occur or if it’s turned OFF
while idling or cooking, then pilot and burners will go
out and not re-ignite upon call for heat by the cycling
pressure switch.
A. Power switch indicator light (red) comes
on.
B. Hi pressure indicator light (amber) comes
on.
C. Low water level indicator light (amber)
comes on.
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VL SERIES STEAMER - ELECTRICAL OPERATION
3. Water level reaches LLCO (low water level cut-
C. Auxiliary gas solenoid valve is energized
and opens to allow gas flow.
D. As long as the ignition control module is
sensing a pilot flame, the internal main
valve (MV) contacts close (N.O.) on the
ignition control module. The main gas
valve is energized and gas begins flowing.
off) probe for the water level control and to the
auxiliary LLCO probe for the auxiliary low level
cut-off control.
A. Power to terminal 9 on the water level
control.
1) LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED lights.
E. Burners light and water in boiler begins to
heat up.
B. Power to terminal LLCO on the auxiliary
low water level cut-off control.
7. Boiler steam pressure reaches upper limit set
point of 11 PSI. (Approximately 15 min.)
1) LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED lights.
A. Cycling pressure switch opens, main gas
solenoid valve de-energizes, gas flow
shuts off and burners go out.
NOTE: LLCO relays will remain energized
and LLCO LED’S will remain lit until the
water level drops below the LLCO probes
or the power switch is turned OFF.
B. As boiler heats up and builds pressure,
some by-pass water/steam is produced
which runs into the steam drain box. This
causes the cold water condenser (CWC)
solenoid to cycle, cooling the drain water.
This solenoid is powered by the CWC
thermostat.
4. Water reaches LL (low level) probe.
A. Power to terminal 2 on the water level
control is present but no switching occurs.
5. Water reaches HL (high level) probe.
NOTE: Steam should not be seen entering a
compartment until the manual steam control arm is
pulled forward and locked.
8. Boiler steam pressure drops below lower limit
set point of 9 PSI and the cycling pressure
switch closes.
A. Power to terminal 6 on water level control.
1) The inverse latching relay of the
board is energized, changing the
state of ILR-1 (N.O.) and ILR-2 (N.C.)
contacts. The inverse latching relay
will remain energized through the
alternate latching path of ILR-1
contacts until the water level recedes
below the low level probe.
A. Boiler steam pressure is maintained by the
cycling of the pressure switch between the
upper and lower set point limits. The
cycling pressure switch continues to
energize and de-energize the main gas
solenoid valve starting and stopping the
flow of gas, which in turn, cycles the
burners on and off. This sequence
2) With ILR-2 contacts open, HL relay is
de-energized, HL-3 (N.O.) contacts
open and HL LED goes out.
3) Water fill solenoid is de-energized.
(boiler fill time approx. 11 min.)
continues until one of the following occurs:
1) Boiler pressurizes to 15 PSI, causing
the high limit pressure switch to open.
At that time, the auxiliary gas valve
de-energizes, shutting off the gas
flow to the burners and the high limit
failure light will come on. This light
will stay lit until the pressure drops
below the lower limit set point of 6
PSI and the manual re-set switch is
pressed.
6. Manual re-set switch is pressed, energizing the
coils on the high limit and low water relays.
A. Contacts 1 & 9 on the high pressure relay
change state and lock from N.C. to N.O.
and turn off the high pressure indicator
light. Concurrently, Contacts 1 & 9 on the
low water relay change state and lock from
N.C. to N.O. and turn off the low water
indicator light.
2) Boiler water level drops below the
LLCO probes for the water level and
the auxiliary low level cut-off controls
which then de-energizes the LLCO
relays, changing the contact state of
LLCO-2 (N.O.) back to open. This de-
energizes the main and auxiliary gas
solenoid valves. The gas solenoid
valves will remain off and the low
water level light will come on and stay
lit until the water level rises above the
LLCO probes and the manual re-set
switch is pressed.
B. Contacts 5 & 9 on the high pressure relay
change state and lock from N.O. to N.C.,
supplying power (NEUTRAL) to one side
of the auxiliary gas solenoid valve.
Concurrently, Contacts 5 & 9 on the low
water relay change state and lock from
N.O. to N.C., supplying power (L1) to the
other side of the auxiliary gas solenoid
valve.
NOTE: For both relays to energize, the high
pressure switch must be closed and the water level
in the boiler must be above the low level cut-off
probes in order for LLCO-2 (N.O.) contacts to close.
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VL SERIES STEAMER - ELECTRICAL OPERATION
A. Micro switch SW1 contacts change state
Cook Cycle
from N.O. back to N.C. (normal starting
position)..
1. A Cook cycle should not be started, until the
initial fill and preheat is completed, in order for
the boiler steam pressure to be within
operational limits.
4. Cooking timer is manually turned off.
5. Compartment power switch is turned OFF,
buzzer is de-energized and power is removed
from the common side of micro switch SW1.
A. Insert product into steamer.
B. Compartment door is closed and screw
handle tightened down.
6. Steamer reverts to preheat cycle until:
A. A cooking cycle is started. i.e.
compartment door is closed and screw
handle tightened down, time is dialed into
timer (past 5 minutes) and the
C. Compartment steam control arm is pulled
forward and latches, allowing steam to
enter compartment.
NOTE: Cool air and condensate exit through the
steam exhaust solenoid valve (N.O.) until
compartment temperature reaches 180°F.
compartment power switch is turned ON.
B. Water level drops below low level cut-off
probe.
D. Time is dialed on timer (past 5 minutes).
C. Power switch is turned OFF.
1) Micro switch SW1 contacts change
state from N.C. to N.O.
NOTE: Burners will re-light after the boiler pressure
drops below the low pressure set point limit (9 psi)
and will stay on until the high pressure set point (11
psi) is reached. As long as steam pressure is within
limits, even while cooking, burners can go off. The
boiler is able to re-pressurize to the upper set point
limit even with all compartments in cook mode.
2) Micro switch SW2 contacts also
change state from N.C. to N.O.
E. Compartment power switch is turned ON.
1) L1 (HOT) to one side of the thermal
switch.
NOTE: The cold water condenser thermostat
remains closed and cold water condenser solenoid
stays energized while cooking. If main water is shut
off after boiler fill, then no cold water is present to
condense steam/hot water and steam vapors exit
the floor drain.
NOTE: L2 (NEUTRAL) is connected to the other
side of the buzzer, steam exhaust solenoid valve,
trip solenoid, pilot light and timer motor.
F. Once compartment temperature reaches
approximately 180°F thermal switch
closes and supplies power L1 (HOT) to:
Water Refill (After Initial Fill)
1) Steam exhaust solenoid valve (N.O.)
energized and closes.
1. Water level drops below low level probe (LL).
A. Power is removed from terminal 2 on the
water level control .
NOTE: Even though steam exhaust solenoid valve
is closed, a small opening exists in the “guillotine”
blade of the valve to allow “limited free venting” of
condensate during a cook cycle.
1) The inverse latching relay is de-
energized, returning ILR-1 (N.O.) and
ILR-2 (N.C.) contacts back to their
original state.
2) Pilot light (red) comes on indicating
timed cooking at 180°F has started.
B. HL relay is energized.
1) Contacts HL-3 close.
2) HL LED comes on.
3) Timer motor energized
2. Cooking Timer times down to approximately
one minute before zero.
3) Fill solenoid is energized and water
flows into tank.
A. Micro switch SW2 contacts change state
from N.O. back to N.C. (normal starting
position).
2. Water reaches LL (low level) probe.
1) Steam exhaust solenoid valve is de-
energized and opens to exhaust
steam and pressure from the
compartment.
A. Power to terminal 2 on the water level
control is present but no switching occurs.
3. Water reaches high level probe.
A. The inverse latching relay of the water
level control is energized, changing the
state of ILR-1 (N.O.) and ILR-2 (N.C.)
contacts.
2) Steam trip solenoid is energized and
unlatches steam control arm allowing
it to return to the rear. Steam supply
the compartment is shut off.
B. HL relay is de-energized.
3. Cooking timer reaches zero.
Page 44 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
2) L2 to the common terminal on the
1) HL-3 opens.
blowdown timer relay; to pin 4 on the
boiler ON/OFF switch; to one side of
the manual reset switch; to one side
of the auxiliary switch(s) mounted on
the side of the auxiliary contactor(s);
to the compartment controls.
2) Fill solenoid de-energized and water
stops flowing into tank.
3) HL LED goes out.
4. The water refill cycle will occur whenever the
water level is below the low level probe and will
not affect the operation of either the preheat or
cook cycle.
F. Unit properly grounded. (Boiler and water
level control share a common ground)
G. Water supply valve on.
Boiler Blowdown/drain
H. Control (cycling) pressure switch closed.
1. Main power switch turned OFF.
A. Boiler blowdown sequence starts.
I.
High limit pressure switch closed.
J. Cold water condenser (CWC) thermostat
open.
B. The blowdown solenoid valve (N.O.) is de-
energized and valve opens to drain the
boiler.
K. Blowdown solenoid valve (drain) closed
and boiler empty.
C. Power is removed from all components
except cold water condenser (CWC)
L. Compartment doors open.
thermostat and solenoid valve. The CWC
thermostat cycles as necessary to lower
the discharge temperature of the water
and condense steam going into the drain.
2. Power switch turned ON. (located on boiler
control box)
A. Power to terminal 2 on the differential
water level control then jumpers connect
to terminal 2 on both the low level cut-off
and auxiliary low level cut-off water level
controls.
ELECTRIC MODELS
This sequence of operation is written for steamers
with electro mechanical water level controls, Cal-
Code boiler controls option and with Prevent
cooking compartment controls. Refer to schematic
diagram number 3941 for a boiler control schematic
and 3962 for a schematic and wiring diagram on
Prevent cooking compartment controls.
B. Power switch indicator light (red) comes
on.
C. Boiler fill solenoid valve is energized and
boiler begins to fill.
INITIAL FILL AND PREHEAT
1. Conditions.
NOTE: The safety circuit remains de-energized
until the water level in the boiler reaches the
low level cut-off probe (minimum level) for the
auxiliary low level cut-off control and the
manual reset switch is pressed. Also, until the
water level in the boiler reaches the low level
cut-off probe (minimum level) for the low level
cut-off control, the low level cut-off control
remains de-energized. The heating elements
will not come on until the manual rest switch is
pressed these conditions are satisfied.
A. Power switch OFF.
B. Manual reset switch OFF.
C. Cooking timers off.
D. Compartment power switches OFF.
E. Unit connected to correct voltage supply.
1) L1 to one side of the boiler fill
solenoid valve; to one side of the
main and auxiliary contactor(s); to
one side of the power on light (red);
to one side of the heat on light
(amber); to one side of the timer
motor; to one side of the cold water
condenser solenoid valve; to one side
of the blowdown solenoid valve; to
terminal 1 on the auxiliary low level
control then jumpers connect L1 to
terminal 1 on the differential and low
level controls; to the compartment
controls.
3. Water level reaches LLCO (low water level cut-
off) probe for the low level cut-off control and to
the auxiliary LLCO probe for the auxiliary low
level cut-off control.
A. Power to terminal 10 on the low level cut-
off and on the auxiliary low level cut-off
control is present. The internal contactor
coil on the water level controls are then
energized.
1) The normally open contacts on
terminals 7 and 8 for both the main
and auxiliary low level cut-off controls
close.
2) The main heater contactor(s) are then
energized.
Page 45 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
1) Boiler pressurizes to 15 PSI, causing
NOTE: Power the internal contactors on
the low level cut-off and auxiliary low level
cut-off will remain, until the water level
drops below the LLCO probes or the power
switch is turned OFF.
the high limit pressure switch to open.
At that time, the auxiliary heating
element contactor(s) are de-
energized, shutting off power to the
heating elements. The pressure
switch will remain open until the
pressure drops below the lower limit
set point of 6 PSI. Boiler water level
drops below the LLCO (low water
level cut-off) probes for the low level
cut-off and the auxiliary low level cut-
off controls, de-energizing the internal
contactor on both controls. This de-
energizes the main and auxiliary
heater contactors, shutting off power
to the heating elements. The heating
elements will remain off until the
water level rises above the LLCO
probes and the manual re-set switch
is pressed.
4. Manual reset switch is pressed (momentary).
A. The auxiliary heater contactor is energized
supplying power to the heating elements
and the heat light (amber) comes on.
1) Water in boiler heats up.
B. Internal relay on manual reset switch is
energized.
1) Normally open contacts close and
lock to provide power to the auxiliary
heater contactor and the heat light
after the reset switch is released.
5. Water reaches LL (low level) probe.
A. Power to terminal 7 on the differential
level control is present but no switching
occurs.
COOK CYCLE
1. A Cook cycle should not be started, until the
initial fill and preheat is completed, in order for
the boiler steam pressure to be within
operational limits.
6. Water reaches HL (high level) probe.
A. Power to terminal 10 on the differential
level control.
A. Insert product into steamer.
1) The internal contactor coil on the
differential level controls is energized.
B. Compartment door is closed and screw
handle tightened down.
a. The normally closed contacts on
terminals 3 and 4 open, de-
C. Compartment steam control arm is pulled
forward and latches, allowing steam to
enter compartment.
energizing the boiler fill solenoid
and the boiler stops filling.
NOTE: The internal contactor coil has a
locking path through contacts on terminals
7 & 8 to the low level probe to keep the
coil energized after the water level drops
below the high level probe.
NOTE: Cool air and condensate exit through
the steam exhaust solenoid valve (N.O.) under
“Full Free Venting” until the compartment
temperature reaches 180°F. When the solenoid
valve energizes and closes, condensate will
continue to exhaust through a small opening
the valve under “Limited Free Venting” until the
solenoid valve de-energizes and re-opens, one
minute before the end of a cook cycle.
7. Boiler steam pressure reaches upper limit set
point of 11 PSI. (Approximately 15 min.)
A. Cycling pressure switch opens, heater
contactor(s) de-energize and power to the
heating elements is removed.
D. Time is dialed on timer (past 5 minutes).
1) Micro switch SW1 contacts change
state from N.C. to N.O.
NOTE: Steam should not be seen entering a
compartment until the manual steam control
arm is pulled forward and locked.
2) Micro switch SW2 contacts also
change state from N.C. to N.O.
8. Boiler steam pressure drops below lower limit
set point of 9 PSI and the cycling pressure
switch closes.
E. Compartment power switch is turned ON.
1) L1 (HOT) to one side of the thermal
switch.
A. Boiler steam pressure is maintained by the
cycling of the pressure switch between the
upper and lower set point limits. The
cycling pressure switch continues to
energize and de-energize the heating
element contactor(s), which in turn, cycles
the heating elements on and off. This
sequence continues until one of the
following occurs:
NOTE: L2 (NEUTRAL) is connected to the
other side of the buzzer, steam exhaust
solenoid valve, trip solenoid, pilot light and
timer motor.
Page 46 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
F. Once compartment temperature reaches
WATER REFILL (AFTER INITIAL FILL)
approximately 180°F thermal switch
closes and supplies power L1 (HOT) to:
1. Water level drops below low level probe (LL).
A. Power is removed from terminal 7 on the
differential water level control.
1) Steam exhaust solenoid valve (N.O.)
energized and closes.
1) The internal contactor coil is de-
energized returning contacts 3 and 4
back to there original state and
energizing the boiler fill solenoid to
refill the boiler.
NOTE: Even though steam exhaust
solenoid valve is closed, a small opening
exists in the “guillotine” blade of the valve
to allow “limited free venting” of
condensate during a cook cycle.
2. Water reaches LL (low level) probe.
2) Pilot light (red) comes on indicating
timed cooking at 180°F has started.
A. Power to terminal 2 on the water level
control is present but no switching occurs.
3) Timer motor energized
3. Water reaches HL (high level) probe.
2. Cooking Timer times down to approximately
one minute before zero.
A. Power to terminal 10 on the differential
level control.
A. Micro switch SW2 contacts change state
from N.O. back to N.C. (normal starting
position).
1) The internal contactor coil on the
differential level controls is energized.
1) Steam exhaust solenoid valve is de-
energized and opens to exhaust
steam and pressure from the
compartment.
a. The normally closed contacts on
terminals 3 and 4 open, de-
energizing the boiler fill solenoid
and the boiler stops filling.
2) Steam control solenoid (trip) is
energized and unlatches steam
control arm allowing it to return to the
rear. Steam supply the compartment
is shut off.
NOTE: The internal contactor coil has a
locking path through contacts on terminals
7 & 8 to the low level probe to keep the
coil energized after the water level drops
below the high level probe.
3. Cooking timer reaches zero.
4. The water refill cycle will occur whenever the
water level is below the low level probe and will
not affect the operation of either the preheat or
cook cycle.
A. Micro switch SW1 contacts change state
from N.O. back to N.C. (normal starting
position).
BOILER BLOWDOWN/DRAIN
B. Buzzer is energized.
1. Main power switch turned OFF.
4. Cooking timer is manually turned off.
A. Power switch indicator light (red) goes out
and power is removed form all boiler
controls except the blowdown timer.
5. Compartment power switch is turned OFF,
buzzer is de-energized and power is removed
from the common side of micro switch SW1.
2. Blowdown timer switch is pressed.
6. Steamer reverts to preheat cycle until:
A. The normally open timer contacts close,
energizing the blowdown solenoid valve
and the cold water condenser valve.
A. A cooking cycle is started. i.e.
compartment door is closed and screw
handle tightened down, time is dialed into
timer (past 5 minutes) and the
B. Boiler begins blowing down and draining
until timer “times out” after approximately
4 minutes.
compartment power switch is turned ON.
B. Water level drops below low level cut-off
probes.
C. Timer contacts re-open and power is then
removed from the blowdown solenoid
C. Power switch is turned OFF.
valve and the cold water condenser valve.
NOTE: Heating elements will come back on, after
the boiler pressure drops below the low pressure set
point limit (9 psi) and will stay on until the high
pressure set point (11 psi) is reached. As long as
steam pressure is within limits, even while cooking,
heating elements can go off. The boiler is able to re-
pressurize to the upper set point limit even with all
compartments in cook mode.
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PAGE PURPOSELY LEFT BLANK
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VL SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATICS, GAS STEAMERS, BOILER CONTROLS
VL2G AND VL3G - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Manual Ignition, Standard Controls
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Electronic Ignition, Standard Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
Manual Ignition, CSD-1 Code Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, CSD-1 Code Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, GAS STEAMERS, BOILER CONTROLS
VL2G AND VL3G - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Manual Ignition, Standard Controls
Page 54 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, Standard Controls
Page 56 of 88
VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Manual Ignition, CSD-1 Code Controls
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Page 59 of 88
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Electronic Ignition, CSD-1 Code Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATICS, ELECTRIC STEAMERS, BOILER CONTROLS
VL2E AND VL3E - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Auto Blowdown, Standard Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, ELECTRIC STEAMERS, BOILER CONTROLS
VL2E AND VL3E - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Auto Blowdown, Standard Controls (contactor - 1 std.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Standard Controls (contactors - 2 std.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Manual Blowdown, Cal-Code Controls (contactors - 1 std. 1 aux.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls ( contactors - 1 std. 1 aux.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls (contactors - 2 std. 2 aux.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
Manual Blowdown, Cal-Code Controls (contactors - 2 std. 2 aux.)
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VL SERIES STEAMER - ELECTRICAL OPERATION
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VL SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, ELECTRIC HEATER CIRCUITS
VL2E AND VL3E - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Standard and Cal-Code/CSD-1 Controls
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VL SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATIC AND WIRING DIAGRAMS, DIRECT STEAMERS, CABINET BASE
VL2D AND VL3D - PREVENT, AUTOMATIC, STANDARD AND MANUAL
See “SCHEMATIC AND WIRING DIAGRAMS - COMPARTMENT CONTROLS”
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VL SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, REGENERATED STEAMERS, BOILER CONTROLS
VL2R AND VL3R - PREVENT, AUTOMATIC, STANDARD AND MANUAL
Manual Blowdown (Older Models)
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VL SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown (Older Models)
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VL SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATIC AND WIRING DIAGRAMS - COMPARTMENT CONTROLS
Prevent
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VL SERIES STEAMER - ELECTRICAL OPERATION
Automatic
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VL SERIES STEAMER - ELECTRICAL OPERATION
Standard
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VL SERIES STEAMER - ELECTRICAL OPERATION
Manual
NO ELECTRICAL COMPONENTS ARE USED WITH THE MANUAL COMPARTMENT CONTROLS OPTION.
THE CONTROLS CONSIST OF A MANUAL COOKING TIMER AND MANUAL STEAM CONTROL ARM TO
CLOSE AND OPEN THE STEAM GATE VALVES.
Page 83 of 88
VL SERIES STEAMER - TROUBLESHOOTING
TROUBLESHOOTING
ALL MODELS
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TESTS OR
MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL
TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST
EQUIPMENT AND REAPPLY POWER TO TEST.
SYMPTOM
POSSIBLE CAUSES
Compartment leaks water around door.
1. Drain screen clogged.
2. Drain line obstructed or not to an open gap drain.
3. Steamer not level.
4. Excessive cooking compartment pressures.
A. On models equipped with the compartment pressure
regulating valve, verify the compartment pressure is 6
psi during cooking. If pressure is higher then adjust the
pressure regulating valve and re-check. See
COMPARTMENT PRESSURE ADJUSTMENT” in
“SERVICE PROCEDURES AND ADJUSTMENTS”.
B. On models with out the compartment pressure
regulating valve, verify the compartment pressure is 6
psi during cooking. If pressure is higher then adjust the
cycling pressure switch and re-check. See “CYCLING
AND HIGH LIMIT PRESSURE SWITCHES (GAS AND
ELECTRIC MODELS)” in “SERVICE PROCEDURES
AND ADJUSTMENTS”.
Cold water condenser not operating
properly.
1. Water supply not on.
2. Plugged spray nozzle.
3. Cold water condenser solenoid inoperative or plugged.
4. Cold water condenser thermostat malfunction or needs
adjustment.
5. No power to cold water condenser solenoid.
1. Compartment door not properly sealed.
2. Worn or damaged gasket.
Steam leaks around door.
3. Drain line obstructed or not to an open drain.
Steam generated inside compartment
when timer or compartment power switch
is OFF.
1. Steam gate valve not fully closing (clogged, dirty or
malfunctioning). See “STEAM GATE VALVE” in “SERVICE
PROCEDURES”.
Heat coming on without water in boiler
(Dry firing).
1. Lime scale (moist) on LLCO water level probe or probe
damaged (shorted to ground).
2. Retention of water in probe canister assembly.
3. Water level control malfunction.
Pressure relief valve opening or leaking.
1. Pressure relief valve malfunction.
2. Cycling pressure switch set to high. See “CYCLING AND HI
LIMIT PRESSURE SWITCHES (GAS AND ELECTRIC
MODELS)” in “SERVICE PROCEDURES”.
Page 84 of 88
VL SERIES STEAMER - TROUBLESHOOTING
SYMPTOM
POSSIBLE CAUSES
Boiler base will not heat or build
pressure.
1. Check incoming voltage.
2. Boiler not filled - check fill solenoid for power, clogging or
malfunction.
3. Water Level Control malfunction. HL-3 relay not energizing
or contacts not closing to power boiler fill solenoid.
4. Water too “pure” for probes to properly conduct electricity.
5. Contactor malfunction (electric only).
6. Heating element inoperative (electric only).
7. Cycling pressure switch open or set too high. Steamer is
cycling on high limit.
8. High limit thermostat open.
9. Problem with auto blowdown timer (older models).
10. Power switch malfunction.
11. Pressure reducing valve malfunction or needs cleaned
(direct or regenerated models only).
12. Low or no steam supply to steamer (direct or regenerated
models only).
Steam output low or slow cooking.
1. Steam gate valve not fully opening or blocked.
2. Cycling pressure switch malfunction or needs adjustment.
3. Steam header line (supply) blockage.
4. Heavy amount of condensate in the pressure controls steam
supply line.
5. Pressure relief valve leaking.
6. Steam supply lines leaking.
Boiler leaks water.
1. Loose water, steam or drain line connections (top or base).
2. Boiler hand hole gasket not sealing.
3. Leak at gauge glass.
Boiler fill solenoid cycling to frequently.
Boiler water level too high.
1. LL probe lime scaled over (dry) or damaged and not sensing
water.
2. Water level control malfunction.
1. Fill solenoid does not shut off.
2. High level probe lime scaled over (dry) or damaged and is
not sensing water (open circuit).
3. Water level control malfunction. HL-3 relay not de-energizing
or contacts not opening.
Boiler does not fill or slow to fill.
1. Water supply not on or pressure too low.
2. Line strainer clogged.
3. Fill solenoid not malfunctioning or plugged.
4. A High pressure pocket in the supply line to the boiler causes
the fill solenoid valve not to open. See ”BOILER NOT
FILLING WITH WATER” in “SERVICE PROCEDURES AND
ADJUSTMENTS”.
5. Water level control malfunction. HL-3 relay not energizing or
contacts not closing to power boiler fill solenoid.
Page 85 of 88
VL SERIES STEAMER - TROUBLESHOOTING
SYMPTOM
POSSIBLE CAUSES
Cooking timer motor does not run.
1. Timer not getting power.
2. Timer motor inoperative.
1. Cooking timer malfunction.
2. Buzzer malfunction.
Buzzer not operating.
Compartment red light and timer do not
come on; excessive time elapses before
they come on; timer stops, the red light
goes out, and the buzzer does not sound
after compartment exhausts steam; time
is set as usual for the product and the
product is overcooked.
1. Thermal switch (load compensator) is set too high.
Short a time between starting and the red 1. Thermal switch (load compensator) is set too low.
light coming on; red light comes on
immediately; time is set as usual for the
product and the product is undercooked.
Cooking Compartment Controls
inoperative
1. Ensure that voltage is reaching control circuit through
compartment power switch when turned ON.
2. On electric heat models with a transformer, check step down
transformer (located in the contactor box) for proper
operation.
3. Check cooking timer function and contact position. See
“SCHEMATIC AND WIRING DIAGRAMS -
COMPARTMENT CONTROLS” under “ELECTRICAL
OPERATION”.
4. Check that timer motor operates when connected to power. If
a problem is found in timer, replace it, do not take timer
apart.
5. On prevent and automatic models check the load
compensator for malfunction.
6. Check wiring for damaged insulation. (no short circuit)
7. Check that all connections and terminals are securely
fastened. (no open circuits)
8. Check that all connections are made according to
compartment control wiring diagram.
Cooking Compartment not venting at end 1. Steam control arm not returning after unlatching (automatic,
of cook cycle (Prevent models) or when
manual steam control arm is released.
standard and manual models).
A. Broken or missing return spring.
B. Packing nut on steam gate valve to tight.
C. Steam control (trip) solenoid malfunction (prevent and
automatic models).
2. Steam exhaust solenoid valve malfunctioning (prevent
models).
Page 86 of 88
VL SERIES STEAMER - TROUBLESHOOTING
GAS MODELS ONLY
SYMPTOM
Burner won’t light.
POSSIBLE CAUSES
1. Gas not on.
2. Ignition control module reset switch in the OFF position or
malfunctioning.
3. Ignition module not receiving power. Check ignition module
transformer for 24VAC output to module on automatic
ignition systems.
4. Steamer not properly grounded and/or polarity of incoming
power is incorrect on automatic ignition systems.
5. Low incoming gas pressure. See “GAS MANIFOLD
PRESSURE ADJUSTMENT” in “SERVICE
PROCEDURES”.
6. Ignition module malfunction.
7. Gas combination control valve malfunction.
8. Boiler not filling. Check fill solenoid for power, clogging or
malfunction.
9. Water level control malfunction. HL-3 relay not energizing
or contacts not closing to power boiler fill solenoid.
10. Water too ”pure” for probes to properly conduct electricity.
11. High limit thermostat open (if equipped).
12. High limit pressure switch open.
13. Cycling pressure switch open or set too high. Steamer is
cycling on high limit. See “CYCLING AND HI LIMIT
PRESSURE SWITCHES (GAS AND ELECTRIC MODELS)
in SERVICE PROCEDURES”.
Burner won’t stay lit.
1. Gas pressure low. See “GAS MANIFOLD PRESSURE
ADJUSTMENT” in “SERVICE PROCEDURES”.
2. Check gas orifice for obstruction.
3. Ignition module malfunction.
Page 87 of 88
VL SERIES STEAMER - TROUBLESHOOTING
POSSIBLE CAUSES
SYMPTOM
Pilot not lit or goes out.
1. Gas not on.
2. Pilot going out due to drafts, excess steam from drain or
steamer not level. Improper venting can direct the pilot
flame away from thermopile or flame sensor.
3. Low incoming gas pressure. See “GAS MANIFOLD
PRESSURE ADJUSTMENT” in “SERVICE
PROCEDURES”.
4. Pilot not adjusted correctly. See “PILOT AND
THERMOCOUPLE ASSEMBLY (GAS MODELS)” in
“SERVICE PROCEDURES AND ADJUSTMENTS”.
5. Check thermopile millivolts. See “PILOT AND
THERMOCOUPLE ASSEMBLY (GAS MODELS)” in
“SERVICE PROCEDURES AND ADJUSTMENTS”.
6. Burners ignite too violently. Check gas pressure to the
steamer. See “GAS MANIFOLD PRESSURE
ADJUSTMENT” in “SERVICE PROCEDURES”.
7. If auto ignition and no sparking - ignition module
malfunction.
8. Wrong pilot assembly used.
Spark Ignitor not sparking.
1. Poor ground between pilot bracket and burner.
2. Loose, broken or damaged lead wires (including ground)
from ignition module to ignitor.
3. Ignitor boot on ignition cable loose, damaged or missing
causing excessive ignition voltage leakage.
4. Ceramic flame rod insulator on ignitor cracked or damaged
from extreme heat.
5. Incorrect spark gap setting. See “AUTOMATIC IGNITION
SYSTEMS (GAS MODELS)” in “SERVICE
PROCEDURES”.
6. Ignition module not receiving power. Check to ensure the
ignition control module reset switch is ON.
7. Ignition module malfunction.
Form 24650 (May 1999)
Printed in U.S.A.
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