a. Disconnect power to furnace and remove vent connector from furnace outlet collar. Be sure to allow time for vent pipe to cool down
before removing.
b. Restore power to furnace and set room thermostat above room temperature.
c. After normal start-up, allow furnace to operate for 2 minutes, then block flue outlet 100 percent. Furnace should cycle off within 2
minutes.
d. Remove blockage and reconnect vent pipe to furnace outlet collar.
e. Wait 5 minutes and then reset draft safeguard switch.
3. Check pressure switch.
This control proves operation of draft inducer blower.
a. Turn off 115-v power to furnace.
b. Remove control door and disconnect inducer motor lead wires from wire harness.
c. Turn on 115-v power to furnace.
d. Set thermostat to "call for heat" and wait 1 minute. When pressure switch is functioning properly, hot surface ignitor should NOT glow
and control center diagnostic light flashes a 31 fault. If hot surface ignitor glows when inducer motor is disconnected, shut down furnace
immediately. Determine reason pressure switch did not function properly and correct condition.
e. Turn off 115-v power to furnace.
f. Reconnect inducer motor wires, replace control door, and turn on 115-v power to furnace.
4. Check auxiliary limits (when used).
a. Turn off 115-v power to furnace.
b. Remove blower access door.
c. Disconnect red motor lead at blower speed selector. Mark terminal for proper re-connection.
d. Replace blower access door.
e. Turn on 115-v power to furnace. Be sure room thermostat is calling for heat.
f. Allow furnace to operate until auxiliary limit activates, but DO NOT operate furnace longer than 4 minutes.
g. If furnace operates for 4 minutes, check/replace limit switch(es).
h. Turn off 115-v power to furnace.
i. Remove blower access door.
j. Reconnect red motor lead, reset switch, and replace door.
k. Turn on 115-v power to furnace.
F.
Checklist
1. Put away tools, instruments, and clean up debris.
2. Verify manual reset switches have continuity.
3. Ensure blower and control access doors are properly installed.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s instructions.
6. Review User’s Manual with owner.
7. Leave literature packet near furnace.
© 1994 RESCO
P.O. Box 1667, Indianapolis, IN 46206
45003r
—20—
Catalog No. 92-33GB-3A5
→
