In AUTO; blower won't come on when i turn heater/AC on.
I have a york 2 stage heater; when i turn the heater on in AUTO the blower won't come on. only when i switfch the fan to ON and then turn the heater on then it works. but then the blower is always on.
what could be the problem?
Re: In AUTO; blower won't come on when i turn heater/AC...
Most likely the heating speed relay on your furnaces IFC board has failed.Unfortunately the entire IFC must be replaced to repair this. you are in need of a professional service tech. The same control handles the blower fan, ignition system and safeties. Not a do-it-yourself repair as wires in the wrong place could cost you a house.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
You can check for continuity of the blower motor by unplugging it and putting your test leads on the terminals of the blower motor. I'm thinking less than 2-3 ohms.
If your trying to check the blower motor module than set your voltmeter to a/c (NOT D/C) voltage. Ground lead on any good ground. The positive test lead will back probe the red with light green wire at the ATC power module. Turn the blower motor speed up and down slowly. You should see the A/C voltage go up and down. If it does and there is no power going to the blower motor and there is power on the dark green wire at the ATC module than the ATC module is bad.
there will be an access panel where the motor is located. 1st thing to check is fuse or circuit breaker feeding the air handler. this is on seperate power from compressor unit outside and usually has a fused or breakered disconnect on the side of the unit. if fuses are good or breaker is not tripped then switch fan mode to on. if blower runs in on but not in auto then it is a thermostat problem. if still no go then turn off power, remove access panel and find the squirrel cage fan blade. make sure it turns freely. it is very common for these motors to go bad. it can usually be removed easily and taken to a motor shop. I use Roy's Electric in Richmond, Va. They can test the motor on the bench and replace it if it is faulty.
the wire diagram should tell you how. it all depends where wires lead to. be very carefull, capacitors can be dangerous. brown usaully go to fan black usaully goes to common red usaully goes to herm or compressor. it all depends where wires come from
You have a blower relay in the furnace that's probably bad. In the heat mode the blower is on a temperature relay, in cooling mode the blower has to come on immediately so there is another relay for cooling. The green wire on the thermostat feeds that relay, so if you go to the furnace and shut the power off and find the green wire from the thermostat that feeds that relay and replace it, being careful to mark all the wires before removing them, also the relay terminals have numbers for identification.