Runaway heating

[Kylewis98]

Like many others, my 3rd gen learning thermostat will randomly (once a month, or so) heat well past the set threshold. We wake up in a sweat, and the only way to get it to stop is to shut it off from the breaker. 

I had an HVAC tech come out today who inspected all wiring and our heat-pump unit, and verified it must be the thermostat itself. I’m attaching photos (if it will let me) of the old thermostats wiring in addition to how our new nest is wired. We are scared to go out of town because we don’t want our house (and cat) boiling while we are gone. Please help!

[DeboraJ]

Hi @Kylewis98,

Thanks for reaching out to the Community! I understand that you are experiencing issues with your Nest Learning Thermostat (3rd Gen) where the heating is turning on unexpectedly. I know how important it is to have everything set properly, especially when you have pets at home, so let me help you out with this!

Before we move forward, I need a little information to provide you with the most accurate steps:

• What other strange symptoms have you experienced since the problem started?
• Are there any error messages? If so, what do they say?
• Does the issue happen with heating only, cooling only, or both?
• Have you experienced any power outages within the last few days or weeks?

Once you provide this information, I will be more than happy to assist you!

Best regards, 

Debora