Bryant Plus 80 Model 376CAV024070 - Won't Fire Up

[dpgreen]

This unit is horizontally mounted. The air blower turns on with the thermostat controls, but the burner never fires up.

After chasing the gas line and ensuring the supply valves are open, I've followed the simple trouble shooting steps on the door:
Turn off thermostat, unplug power, turn gas switch to off, wait five minutes, turn switch back to on, plug in power, turn on heat via thermostat.

The blower powers up, but not the gas; no fumes, no flames, nada.

I checked what I think are the two "Manual Reset Limit Switches", and they don't seem to be tripped.

Anybody have any advice for me?

Thanks!

[dpgreen]

Flashing LED

Forgot to mention, there's a flashing red LED in the air handling half of the unit.

From the Label on door panel labelled "SERVICE";
LED Code = Rapid Flashing
STATUS = "Line voltage (115v) polarity reversed. If twinned, refer to twinning kit instructions."

I'm new to this house - landlord says furnace use to work... not sure if this LED code is relevant or not.

Cheers!

[paul52446m]

Forgot to mention, there's a flashing red LED in the air handling half of the unit.

From the Label on door panel labelled "SERVICE";
LED Code = Rapid Flashing
STATUS = "Line voltage (115v) polarity reversed. If twinned, refer to twinning kit instructions."

I'm new to this house - landlord says furnace use to work... not sure if this LED code is relevant or not.

Cheers!

Have you seen the furnace work before? Some times people do strange things. Maybe you better check the polarity. See if you can find where the power goes to the electronic board. Check from the black wire to cabinet ground and see if you get 120 volts. if you don't then check from the white wire to cabinet and see if you get 120volts. If you do then reverse the two wires. The next thing to happen after inducer pressure switch has to close, 24 volts in 24 volts out. after that you should get ignition to lite pilot.
Paul

[dpgreen]

Thanks a lot Paul.

"Sometimes people do strange things" - your sure said it there!!

I've never seen the furnace work - just the blower. I'm not at the property now, but later this week will do the voltage test you described.

Sounds like after testing the polarity, you suggest testing that the inducer pressure switch is working, by testing that it has 24 volts to it, and that it is closing & showing 24 volts out.

I'll post my results. Any more tips much appreciated!
Best,
D

[dpgreen]

Somebody Did Something Strange

Too Simple; Good Eye Paul!!

Chased the wires & found 120 across white to ground, and zero from black to ground. Switched the wires where they connected to the board (same sized blade terminals), and we are warm now!! (first the LED blinked: 1 fast, 2 slow for a couple of minutes, then she powered up & the burners kicked on).

I guess it never worked before... Or had a bad servicing... Strange.

Many Many Thanks! Local HVAC shop = 1 hour minimum at $100/hr.

Best,
d

[paul52446m]

Too Simple; Good Eye Paul!!

Chased the wires & found 120 across white to ground, and zero from black to ground. Switched the wires where they connected to the board (same sized blade terminals), and we are warm now!! (first the LED blinked: 1 fast, 2 slow for a couple of minutes, then she powered up & the burners kicked on).

I guess it never worked before... Or had a bad servicing... Strange.

Many Many Thanks! Local HVAC shop = 1 hour minimum at $100/hr.

Best,
d

glad to help, stay warm. paul

[brettyg]

I hate stupid furnace problems like that