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12 is usually a code we get when unit was calling for heat when power was turned on to furnace.Blower should run 90 seconds and stop the error code go away.So lets wait the 90 seconds ,see if we get a different code or if furnace will work
Does the 12 error go away after 90 seconds?
Ignore the phone call offer It is auto generated,We can continue here
OK now call for heat and tell me if heat comes on or we get a different code.
Do this. JUmp the R and W terminals on furnace control board where thermostat wires connect and tell me if it comes onhttp://i.imgur.com/JprQdYv.png
Jump the terminals on the board
Connect them together
Yes or a paper clip
needle nose pliers, straightened paper clip, piece if wire,etc
OK what error code now?
Get an error code?
Was power already on and the 90 second cycle complete when you jumped r and w, then 12 came back?
Yes, Allow the 90 seconds cycle and fan to stop.The jumper R and W. Furnace should come on or we should get a different code.Tape switch if you need to
Allow the 90 seconds and see if furnace starts or we get a different error
33 means we have an open limit. Do you know what limits look like?Count again (NO 32 listed in manuall)
GIve me model on furnace and tell me what your panel says for 32.
OK next tell me if the small vent motor ever came on?
OK that is your problem.THe vent motor where vent connects has to start to close the pressure switch. Check and see if we are getting 120v to vent motor when you call for heat
Either the motor is failing or board is failing not sending power to that little motor. You will need a meter though to verify which
No fuse. Sporadic points more towards the board as they develop stress cracks. I would want to check with a meter first though before just telling you which
Absolutely.I will guide you in troubleshooting.
The motor is about 100 bucks and board is about 240
Make sure the connections are not loose too
Yes and go to MY Questions.That will bring you here
Keep an eye on it and let me know if it quits again we will go from here
Thanks for letting me work with you this point