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Intertherm Model T3QC-030K Contactor Problem

Posted: Wed Nov 02, 2011 9:54 pm
by Crabbasket
Hello all,

I'm new to this site as a thread poster, but trust me, I've been lurking around for sometime gathering much needed information about other problems people have already addressed. This site has been extremely useful in helping me fix common mobile home issues as well as finding the parts I need to do the job correctly. However, I have a problem with my outside air unit that I cannot seem to figure out and I hope someone could help with some advice.

The outside unit is an Intertherm Model: T3QC-030k, Serial #:T3Q9601-09489
Earlier this summer the fan and compressor stopped turning on when the air was turned on. Inside fan and blower came on just fine but only blew room temp air into the house. I tested the capacitor and found that it was bad, so I replaced it but I can't recall the model number at the moment. This seemed to only work temporarily as the unit only pulled the relay sporadically, maybe once a week. I propped a stick to hold close the contactor when I needed to cool down the house. The air was cold but had to be rigged for it to work. Not a permanent fix by any means.

This fix was only temp. so I replaced the single pole contactor with a two pole contactor by fasco, Model: H230A, 30_FLA_40A_RES, 24VAC. The guy at the parts stored said it should be the equivalent and work fine. I installed the part and the compressor kicked on about 10min. after I turned on the T-Stat. To no avail, I'm still having the same issues with the contactor not pulling. I tested the contactor and it only read 7 ohms, so I returned it and got a new one. I installed and the compressor is still not coming on. I replaced my T-Stat with a Filtrete 3M-22 thinking maybe it was bad too. This didn't work either. The T-stat is obviously sending a signal because inside fan and blower are coming on, right? The outside unit makes an audible clicking sound like it wants to turn on but never pulls the contactor. If I let the unit sit for a few days without use it might kick on or turn over, but not likely. Any ideas? Does my defrost board need to be replaced? It is cold now and time for heat, but I really don't like having to go outside and hold the contactor closed for the heat to run. I'm at a loss so any help is truly appreciated.

Thanks, Zack

Re: Intertherm Model T3QC-030K Contactor Problem

Posted: Tue Nov 08, 2011 8:26 pm
by Mark
Are you getting a strong 24-26 volts to the bottom terminals of the contactor? Any less and it won't hold the contactor closed.