1. Remove upper inducer housing drain connection cap. (See Fig. 45.)
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. 46.)
5. Remove funnel and tube from inducer housing and replace drain connection cap and clamp.
PROCEDURE 3—PURGE GAS LINES
WARNING: 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.
If not previously done, purge lines after all connections have been made and check for leaks.
PROCEDURE 4—SEQUENCE OF OPERATION
CAUTION: FURNACE MAY NOT OPERATE
Failure to follow this caution may result in furnace operation stopping and water pipes freezing during cold weather.
Furnace control must be grounded for proper operation, or control will lock out. Control is grounded through green/yellow wire routed
to gas valve and burner box screw.
Using schematic diagram, follow sequence of operation through different modes. (See Fig. 34.) Read and follow wiring diagram carefully.
NOTE:
If 115-v power supply to furnace or blower access panel switch is interrupted during a call for heat, blower operates for 90 sec when power
is restored before heating cycle is resumed.
A.
Heating Mode
(See Fig. 31 for thermostat connections.)
The wall thermostat
″
calls for heat
″
, closing the R to W circuit. The furnace control performs a self-check, verifies the pressure switch
contacts PRS are open, and starts the inducer motor IDM.
a. Inducer Prepurge Period- As the inducer motor IDM comes up to speed, the pressure switch contacts PRS close, 24 vac power is
supplied for a field installed humidifier at the HUM terminal and the control begins a 15-second prepurge period.
Fig. 45—Inducer Housing Drain Cap
A94208
Fig. 46—Filling Condensate Trap
A94209
—49—
