mobilehomerepair.com

Hello,
I've got this heat pump a/c unit in my house and have lost the blower. I've had troubles with the a/c all summer, but now I need to get the heat fixed to limp through the winter (I can't afford a new a/c yet.).

There's a buzzing noise that comes from the unit whenever I set the t-stat for the heat to come on, so I just cut it off.

I've looked around the forum to try and find the answer, but no luck. Thanks for providing all the help and answers you guys do.

Jimmy

Hi Jimmy,

Open it up and see if you can narrow down what is buzzing. You have a contactor and a couple of relays in there.



Thanks,
Robert

Thanks Robert,
I'll get my wife to help me this afternoon when I get off of work. THANKS!

Robert,
When we turn the t-stat to heat, the buzzing sounds like it's coming from the front of the motor. I can tell you one thing I noticed, the motor spins when switched to heat; but not when cool mode.
I wish I could be more specific but I'm lost on this stuff. Thanks for your help.

Probably a bad fan relay.



Thanks,
Robert

Hey Robert,
Is there a way to check to make sure that's the problem? I have a multi-meter and am pretty familiar with using it on a car. I see that they're not that much through you guys and want to make sure of what kind of hit I'm gonna take in the wallet. LOL! Thanks again for all of your help!

There are two relays, one is NO (normally open) and one is NC (normally closed).


The normally open should get a 24vac signal across the coil terminals which should close the contacts to the blower cooling speed.


You should read 0vac across those contacts and the black wire going to the 6 pin molex connector plug from the relay should read 120vac to ground.



Thanks,
Robert

Robert,
I checked the relays and you were right. I couldn't find them locally, are the ones I need to order the 621898 and 621899? The pictures match the labels on the relays, I just want to make sure.
Thanks again.

Hi,

Yes.

Relay # 621898 can be seen and ordered here by paging down:

http://www.aberdeenhomerepair.com/store ... esults.php


Add to cart and and then type 621899 into the search window to continue shopping.



Thanks,
Robert

Robert,
I got the relays in and put them in, no problem there....but the buzzing is still there. The a/c cuts on like normal now...so I'm glad that's fixed. There's a lot of evidence of condensation, wetness from the coils above, but the electrical up in there looked mostly unaffected (no rust). When you call for the a/c at the t-stat, normal now; when you call for the heat...buzzing and the coils smell like they're burning but not that hot at the unit. Call for the fan...normal. I'm stumped...any ideas? Would pictures of my setup help?

Jimmy

Hi Jimmy,

Is it just the buzzing sound when in heat mode or is the blower not working in heat mode as well ?



Thanks,
Robert

Robert,

The fan works in heat mode.

Jimmy

IF everything is working properly, but you still hear a buzzing, then you will have to try and determine where the buzzing is coming from.


May be the transformer or the contactor if you did not replace it.



Thanks,
Robert