10 year old American Standard furnace with no flame, how did I do troubleshooting?
This morning I noticed that the furnace was running in heat mode, but cold air was coming out of the registers. I pulled the cover off and found that the burners were not igniting. I checked the resistance of the igniter and it seems to be fine.
Next I checked the impeller motor and found that it was not turning on. I disconnected the impeller and hooked it up to a 120 volt source and it turned as expected. Given that the impeller is wired directly to the control board, I think the control board is the problem.
I see the control board on eBay for between $70 and $100 dollars. Is there anything else I should check before replacing the control boards? I expect one of the power relays on the board went bad, but I don’t think I can test the relays without removing the board. It’s probably not worth the hassle of desoldering a relay and soldering on a replacement. Or is it?
This morning I noticed that the furnace was running in heat mode, but cold air was coming out of the registers. I pulled the cover off and found that the burners were not igniting. I checked the resistance of the igniter and it seems to be fine.
Next I checked the impeller motor and found that it was not turning on. I disconnected the impeller and hooked it up to a 120 volt source and it turned as expected. Given that the impeller is wired directly to the control board, I think the control board is the problem.
I see the control board on eBay for between $70 and $100 dollars. Is there anything else I should check before replacing the control boards? I expect one of the power relays on the board went bad, but I don’t think I can test the relays without removing the board. It’s probably not worth the hassle of desoldering a relay and soldering on a replacement. Or is it?