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4.
Connect a manometer to gas control outlet (manifold)
pressure tap.
5.
Set room thermostat to its highest temperature.
6.
Turn on electricity at electrical disconnect switch
located next to furnace.
7.
Diagnostic light on Fan Timer should be on and cycling
bright-dim -bright-dim...
8.
Draft inducer should run and pilot igniter should glow
but pilot burner should not light. Manifold pressure
should remain at zero.
9.
Turn gas control switch to ON position.
10. Pilot burner should light and ignite main burners. It
may take several minutes to purge gas line before pilot
burner lights.
Wait 30 seconds after main burner
ignition for main blower to start.
11. Cycle electrical disconnect switch next to furnace on
and off. Watch at least three ignition cycles. Pilot
should ignite main burners smoothly.
12. Burner flames should look the same with circulation
blower on and off.
13. Remove manometer from gas control and replace
outlet pressure tap
14. Use a commercial soap solution made to detect leaks
and check all gas piping connections. Bubbles indicate
gas leakage. Seal all leaks before proceeding.
15. Replace burner access panel using three screws
removed in step 2.
16. Set room thermostat to desired setting.
SECTION 22. SETTING BLOWER
TIMINGS
Heating blower on-delay is fixed at 30 seconds from when
main valve opens. It is not adjustable.
Heating blower off-delay is adjustable to one of four times:
60, 100, 140 or 180 seconds. Heating blower off-delay is
factory set at 140 seconds. If a different blower off-delay is
desired, do the following:
1.
Find two small switches located near 24-volt terminal
strip on Fan Timer.
2.
Determine switch settings for desired heating blower
off-delay. See Figure 23.
3.
Set switches on Fan Timer using a small screwdriver.
NOTE: Cooling blower off-delay is fixed at 60 seconds and
is not adjustable.
Figure 23. Heating Blower Off-Delay.
SECTION 23. MAINTAINING
FURNACE IN GOOD WORKING
ORDER
WARNING: Use replacement parts listed in parts
list only. Use of incorrect parts on this furnace could cause
improper furnace operation, resulting in damage, injury or
death.
WARNING: Failure to disconnect electrical power
before servicing furnace could result in electrical shock or
death.
Inspection and cleaning by a qualified service person
should be performed once each heating season. Make
sure the inspection includes each of the items listed below.
??
An operational check of the entire system. Assure that
furnace is operating properly and safely.
??
Vent pipe must be in place, slope upward at least 1/4
inch per foot and must be physically sound, without
holes or loose connections.
??
All venting components including vent pipe and vent
terminal must be clear and free of obstructions.
??
Condensate drain system must be clear and free
including all inte rnal and external hoses and
condensate trap.
Check for signs of condensate
leakage.
??
Furnace-room- or closet- combustion and ventilation
air openings must be clear and free.
??
Furnace combustion-air opening must be clear and
free.
??
Return air duct must be physically sound, sealed to
furnace casing and ending outside the space
containing furnace.
??
Supply air ducts and return air ducts must be clear and
free, and without air leaks.
??
Registers and retu rn grilles must be open and
unobstructed by rug, carpet or furniture.
??
The furnace must be well supported without sagging,
cracks, or gaps around the base.
Page 26
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