DuoTherm/Tstat issue

ibrick

Member
When I turn the air conditioner off at the stat the fan stops but the compressor keeps running.

The same happens when I switch the stat to heat. The only way to now turn the compressor off is at the breaker.

Do I need a new stat?

Thanks
Rick
 
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rick_h

Active Member
I think the problem is likely along the lines of a stuck relay(motor contactor). You will likely need a tech to diagnose/repair this problem. Until you have it fixed you should leave the breaker turned off.
 

caissiel

Senior Member
I was asked to help a friend with his AC problem, The compressor kept going while the the fan was off. He had his unit serviced and they wired the AC connections wrong, so I fixed it by wiring it in the AC Panel per the included diagram. This needs attention right away before compressor overheats.
 

ibrick

Member
Thank you all for your responses.

I think it might be the relay as it has worked perfectly until 2 weeks ago. So that eliminates incorrect wiring.

2 weeks ago the compressor started having difficulty restarting while in use. I would shut the AC off for an hour or 2, then restart the AC with no problem until it would repeat the compressor restart issue after a few hours of use.

This latest episode of the compressor continually running even with the stat calling for off is new. I will call Dometic tomorrow and schedule a service call.

Thanks again for pointing me in the right direction.
 

SLJKansas

SLJKansas
Mine did that about a month after I bought my Big Horn, it took a new control board in the AC unit. T stat was ok.
 

timdebs

Well-known member
Mine was doing the same thing. Took it to a Dometic Tech and he had to replace the control board also, all covered under warranty.
 
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