AC Fan runs when heat is on

mike395 · 12-25-2011, 01:19 PM

Merry Christmas everyone!
I set the wall thermostat to heat and the furnace and blower work just fine, but what puzzles me is that the AC fan runs as well and bringing in cold air. I tripped the AC breaker to keep the AC from running. Has anyone heard of this before. I have a 2011 Cougar 318SAB.

Any insight will be appreciated.

Mike

SteveC7010 · 12-25-2011, 02:35 PM

Quote:

Originally Posted by mike395

Merry Christmas everyone!
I set the wall thermostat to heat and the furnace and blower work just fine, but what puzzles me is that the AC fan runs as well and bringing in cold air. I tripped the AC breaker to keep the AC from running. Has anyone heard of this before. I have a 2011 Cougar 318SAB.

Mike, in this case, the make and model of your AC and your thermostat the primary thing you need to tell us about. A pic of your thermostat would be super useful, too.

Have you checked the thermostat to make sure the "cool" is off? In some systems, the fan in the AC will run even when the heat is on if the switch is set to "cool."

There may also be a "fan" switch on the thermostat. That should be off as well if it only affects the AC.

mhs4771 · 12-25-2011, 04:54 PM

Ditto, I think if you have the Dometic Comfort Control Center there is a fan only setting and it needs to be set to off. There must be some sort of glitch as a lot of folks have had that same problem with the CCC. You would think that if you were calling for heat it wouldn't run the AC fan, but it does if it isn't set to off.

mike395 · 12-26-2011, 07:46 AM

I will check the thermostat and post a picture soon. It now makes sense to me that the fan should be set to the off postion. My 2006 trailer had the older style thermostat with selectable fan fan positions. I guess I missed that in the instruction manual. Thanks for the help and Happy New Year.

Mike

jje1960 · 12-26-2011, 09:42 AM

Make sure your AC fan is set to Auto mode. It's probably on low or high, which means it will stay on while the heat is on. I've actually used it in that mode to distribute the hot air, however it needs to be on auto if you don't want it on.

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