FIRE HAZARD
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
This furnace is equipped with a manual reset limit switch in
the burner box area. The switch will open and shut off power
to the gas valve if a flame rollout or overheating condition
occurs in the burner enclosure area. DO NOT bypass the
switch. Correct inadequate combustion-air supply, compo-
nent failure, or restricted flue gas passageway before resetting
the switch.
Step 2—Prime Condensate Trap With Water
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 48.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 49.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
Step 3—Purge Gas Lines
After all connections have been made, purge the gas lines and
check for leaks.
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in a fire, explosion,
personal injury, or death.
Never purge a gas line into a combustion chamber. Never test
for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections, as specified in
″
Gas Piping
″
and
″
Start-up Adjustment, and Safety Check
″
sections of
these instructions.
Step 4—Sequence of Operation
Using schematic diagram in Fig. 36, follow the sequence of
operation through the different modes. Read and follow diagram
very carefully.
NOTE:
If power interruption occurs during
″
call for heat
″
(W/W1
or W/W1 and W2), the control will run the blower for the selected
blower off delay period after power is restored, if the thermostat is
still calling for gas heating. The amber LED will flash code 12
during this period, after which the LED will be ON continuous as
long as no faults are detected. After this period, the furnace will
respond to the thermostat normally.
The blower door must be installed for power to be conducted
through blower door interlock switch ILK to furnace control CPU,
transformer TRAN, inducer motor IDM, blower motor BLWM,
hot surface igniter HSI, and gas valve GV.
Fig. 48—Inducer Housing Drain Cap
A99118
Fig. 49—Filling Condensate Trap
A99119
44
