NEST changes temperature on its own

[Bloodhound]

Why is my temperature changing without following my schedule.  My Gas Bill last month went through the roof.  My set schedule has not changed.  I was home today for illness and all of a sudden I'm cooking.  Went to the thermostat to see what the temperature was and noticed the thermostat was 6 degrees higher than my schedule... what?  This has happened before when I have had gatherings at the house.  Always thought it was one of the guests.  Not anymore.  I was the only one here today. Checked it at 7 am this morning. Just fine.  Noon Boom!  What's up?  Broken Nest?   Time to change?  😞

[lnube]

I began having this issue after buying a new 3rd gen thermostat recently, when we installed new HVAC unit. Either the app or the thermostat is changing the set temperatures starting at midnight, sometimes by 8-9 degrees hotter than I have set, and sometimes 1 degree up and down several times. I have followed all the suggestions on support, have never had learning turned on, do not have Google Assistant controlling my thermostat, the wires are solid copper. I’ve had Nest learning thermostats for years and haven’t had this problem until I bought this new one. There was a string of complaints in 2022 of the same issue with NO help from nest. The message on history when it changes the temperature is the schedule was changed by input from me, while I’m sound asleep. I’ve contacted Nest support twice. 1st time the told me  it was my HVAC system. The company has examined every inch of the system and can’t find a problem with it. It’s a Trane 2 stage system, gas and air. 2nd time I contacted I was told to reset the schedule. I have a background in programming and system installations, and logic tells me there is a problem with the app or the thermostat, especially with others having the same issue. Tired of Nest not working to fix this problem.

[WasBufNowWas]

I just started having this problem as well, though I assumed it’s because my thermostats might be old. The culprit is a downstairs thermostat of a pair on zoned heating. The schedule clearly says 63° and it’s 70 downstairs. The upstairs is literally off (during the winter) and it got up to 79°…

[zoeuvre]

Hi folks,

Uh-uh! I'm sorry to hear that the temperature on your thermostat changes on its own. Are you located in North America or Europe? What type of Nest Thermostat do you have? Also, have you tried any troubleshooting steps? If yes, would you mind listing them?

@lnube, do you have the Case ID from your conversation with support? If you can provide that here, I'll look it up and see how I can continue to help.

Keep us posted. 

Best,

Zoe

[lnube]

My case ID is 8-9067000035886. I’ve done every trouble shooting task recommended. At first it was only happening on my new thermostat, so we swapped it with one we’ve had for several years. Then both started doing it. I’ve completely reset one of the thermostats on 2/1. The history showed it only changing settings at programmed times. Yesterday it began changing the schedule by 1 degree up and down 5 times while it was performing the early setting to reach temperature by 10 pm. There was no history for 2/2. I’m waiting at least 2 weeks before I determine if it is functioning properly, but the fluctuating temperatures last night is leading me to believe it isn’t. The 2nd nest thermostat we had our hvac person switch out for a Honeywell on 1/31 because it was turning on our compressor when nothing, heat or air, was running. So far with the Honeywell have not had that issue. Still,  waiting at least 2 weeks.

[sicsacol]

Hi there,

@lnube I see you've tried some troubleshooting steps but the issue persists, when you get a chance please fill out this form, I'd like to learn and get more about this issue.

let me know once you're done.

Cheers,

Jonathan

[BrettG]

I have this same issue. I wake up too hot, go to the thermostat and it's set 2 degrees higher than it should be according to my schedule.