Furnace won't work in "Auto" mode - http://www.hvacmechanic.com/ Forums
Original message
| baldrick
 |  "Furnace won't work in "Auto" mode"
, posted Tue 25 Oct 12:41  
My Lennox gas furnace is controlled by a Lux thermostat. I kicked the heat on last night and I can hear the furnace firing, but the blower doesn't come on. If I swith from the "Auto/On" mode to "On", the blower kicks on and I have heat. Strange though, because when I initially switched to "On" it didn't immediately come on. It took about 10 minutes to come on. Any ideas?
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Replies:
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| Freon
| "Re(1):Furnace won't work in" , posted Tue 25 Oct 13:45:
Without calling for heat, switch the blower (fan) to ON. Does the blower start immediately? Do you feel good air flow from the supply registers? If the answer is 'yes' to both, then the blower motor appears to be fine and the problem is most likely in the heating circuit relays/timers (usually integrated in the control circuit board unless an old furnace) that switch the blower on.
If the blower does not start immediately or if you feel weak air flow from the supply registers then you need to check to see if there's power at the motor leads where they connect to the control board. If there's power to the blower motor and no blower (or weak blower), you may have a blower motor capacitor problem(if PSC motor) or a motor problem. If there's no power to the motor leads, then it is likely both heating/cooling timer/relay circuits have problems.
[this message was edited by Freon on Tue 25 Oct 13:50] |
| | baldrick
| "Re(2):Furnace won't work in" , posted Tue 25 Oct 18:18
Thanks Freon. Everything looks good without calling for heat.
Repair in Atlanta anyone?
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