Nest 3rd Gen Learning -Having Issues

[terdallaujar]

I installed my Nest back in Oct 2025 and it's been wording fine up until lately. We have a heat pump for both heating and cooling. Using the heat, it displayed 72° but when you walk away it showed 79°. I checked all the settings and it seemed fine. So I reset it back to default. We turned the breaker off and then back on. I could not get the heat to come back on and it got down to 23° last night. Got up this morning and the heat was on. I looked at the thermometer on my clock and it showed 59° It's now taking forever for it to come up to 72°.

Any idea what might have happened or what I did wrong?

[moralesvicente]

Hi @terdallaujar, 

Thanks for reaching out to the Google Nest Community. I’m sorry to hear that your Nest Learning Thermostat (3rd gen) started showing temperature discrepancies (reading 72° but actually was 79°). After you performed a factory reset and cycled the power, you could not get the heat back on and got down to 23°. In the morning the system failed to kick in; it was showing 59°, and it's taking too much time to reach 72°. No worries; it’s a pleasure to help.

I appreciate the time and effort you took to complete the previous steps described in the post. To effectively troubleshoot, could you please answer the following questions?

• Are there any error messages? If so, what are they exactly?
• When was the last maintenance check for your HVAC system?
• Have there been any recent changes or upgrades to your HVAC system?
• Have you experienced any power outages within the last few days or weeks?
• Can you share more details about the power information on your thermostat? On your device, go to Settings > Tech Info > Power info.
• Could you please attach a picture of your wiring system connected to the thermostat?

If you have any additional information to share, let me know. 

Regards, 

Daniel 

[terdallaujar]

Thank you for responding.  It was user error.  My husband is on oxygen and I put his oxygen concentrator under the nest to get it out of the way.  It puts off heat.  That's when the nest started having issues.  Moved it somewhere else and it works fine.

I'm a dummy!

[moralesvicente]

Hello @terdallaujar, 

Thanks for getting back to me. I’m glad to know that the trouble has been resolved. If you have any other questions, please don't hesitate to reach out to this forum. 

Best regards, 

Daniel