66441-YUM-D-1011
If the furnace continues to lock out, a qualified service techni-
cian should be called to determine the cause of the problem.
bustion and ventilation. Adequate air is important to the safe
and proper operation of the unit.
HEATING SYSTEM INSPECTION
It is the owner's responsibility to insure that an annual inspec-
tion of the entire heating portion of the unit is made by a qual-
ified service technician. This should include inspection of the
burner, heating element and flue for any corrosion or soot
accumulation which may require cleaning and also checking
of burner and controls for proper operation.
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in dan-
gerous operation, serious injury, death or property damage.
Improper servicing could result in dangerous operation,
serious injury, death or property damage.
In addition, at least once during the heating season, the
owner shall make a visual inspection of the flue outlet for evi-
dence of black soot or blockage of flue outlet by leaves or
other debris. If any soot is found, it is recommended a quali-
fied service technician be called immediately. If any blockage
is found, it must be cleared immediately.
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Before servicing, disconnect all electrical power to fur-
nace.
When servicing controls, label all wires prior to discon-
necting. Reconnect wires correctly.
Check for obvious signs of deterioration of the unit. Check
that the return and supply ducts attached to the unit are
sound and air tight. Check that the unit's physical support,
concrete slab or roof curb, is sound and not in need of repair.
Make sure there are no gaps between the roof curb and the
unit where rain could leak into the building.
Verify proper operation after servicing.
Start the furnace. The vent motor should start, the igniter will
start to spark and ignite the pilot flame. After a short delay the
main burner should ignite. If it does not, contact a qualified ser-
vice technician for assistance. Check the appearance of the
main burner flame. Adjust burner shutters so no yellow flame is
observed in the heat exchanger tubes. (See Figure 3.) If flame
adjustment cannot be made, obtain the assistance of a quali-
fied service technician and refer to the PILOT CHECKOUT
and BURNER AIR SHUTTER ADJUSTMENT sections in the
UNIT INSTALLATION INSTRUCTION.
Prior to any of the following maintenance procedures, shut
off all power to the unit, to avoid personal injury.
EXPLAIN UNIT FUNCTION
When the system is functioning properly, show the owner the
location of all disconnect switches and the thermostat.
Explain how to start and stop the unit and how to adjust tem-
perature settings within the limitations of the system. Advise
that the flue exhaust hood surface and the immediate area
will experience high temperatures during the heating cycle,
and that all unauthorized personnel and debris must be kept
away from this area.
GENERAL MAINTENANCE
In order to insure long and trouble free service from your sys-
tem, we recommend periodic inspection, cleaning, lubrication
and adjustment by your installing Dealer/Contractor. Be sure
to ask about this service. For those who prefer to do-it-your-
self, please follow the instructions listed below to care for
your system.
FIGURE 3 - TYPICAL FLAME APPEARANCE
BURNER AND PILOT CHECK
Periodically (at least annually at the beginning of each heat-
ing season) make a visual check of the pilot and main burner
flame. If necessary, adjust main burner primary air shutters to
give a distinct, sharp blue flame as explained under BURNER
AIR SHUTTER ADJUSTMENT. If it is not possible to adjust
for the proper flame, the burners may need cleaning.
Snow or debris should not be allowed to accumulate in or
around the unit. Do not permit overhanging structures or
shrubs to obstruct outdoor air discharge, combustion air
inlets or vent outlets on your unit. These provide air for com-
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Johnson Controls Unitary Products
