AC is coming on in Heat mode when I have the fan running.

Redacted — Thu, 12 May 2022 22:05:17 GMT

Notice this for the first time today. I haven't switched over from Heat mode to Cool mode yet because my house is perfectly fine with the windows open and the HVAC fan running. However, now when I try to run only the fan, it will turn the AC compressor on. When I go to the thermostat to see what it's doing, I can see the blue "cooling" background for a split second before it goes black again. My understanding was that it should not be running the AC unless it's in Cool or Heat-Cool mode. The only way I can prevent it from running the AC is if I turn it completely off, which is annoying in that I can't run the fan that way either. Whatever it's doing can't be right, in that I use a dust cover on the AC unit until I switch to cooling and it is NOT a good idea to run the AC with the cover on. Who knows what could have happened if I hadn't been home to catch it...

Is there any way to prevent the AC from coming on unless it's in Cool or Heat - Cool mode? And yes, it has been wired correctly for 5 years and has never done this before this spring.

Re: AC is coming on in Heat mode when I have the fan running.

Ryan_G — Wed, 15 Jun 2022 21:32:03 GMT

Hey folks,

Thanks for visiting the Google Nest Community.

Since this thread hasn't had activity in a while, we're going to close it to keep content fresh.

If you have additional questions, feel free to submit another post and provide as many details as possible so that others can lend a hand.

Hope this helps!

Kind regards,

Ryan

topic Re: AC is coming on in Heat mode when I have the fan running. in Nest Thermostats

AC is coming on in Heat mode when I have the fan running.

Re: AC is coming on in Heat mode when I have the fan running.