Thermostat resetting to 65 randomly. Anyone else having a similar issue?

Hi everyone,
I’ve been using the SmartThings platform for a while now, but this is my first time posting on the forums here.

I recently seem to be having an issue with my thermostat resetting it’s self somehow to 65 degrees for the heating setpoint. It’s an RCS TZ45, and I was originally using the default Z-wave thermostat device handler for it. I had no issue with this configuration. I eventually moved to using the rboy customized Thermostat device handler here: and was having no issue for a while. Randomly, about a month ago, I noticed my thermostat had set its self to 65. Nothing in my automations sets the thermostat to this temperature and the thermostat home/away settings don’t either. I thought the device handler might have been having some issues, but I combed over the code and see nowhere that it hard codes 65 degrees anywhere. I finally set the device handler back to the SmartThings default Thermostat handler, and it continues to have this issue. Both device handlers have this problem now. The thermostat device in the app also doesn’t show any logging showing that it was set to 65.

I’ve double and triple checked all of my automations and smartapps that touch the thermostat and nothing changes to 65 degrees. Everything sets to either 66 or 70. I contacted SmartThings support about the issue, but they told me there wasn’t much they could do since I was using a different device handler and a device that wasn’t certified for SmartThings, even when told that it was happening with the standard device handler as well.

I was wondering if anyone else has seen this issue, or knows what might be going on? It sucks waking up to the house being 65 degrees in the morning because it randomly reset its self sometime throughout the night. I’m also contemplating that it might be that the thermostat has just crapped out, but it’s a very strange issue for something to be firmware or hardware related.

Thanks in advance for any feedback!

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Check the thermostat itself for schedules. I had a CT30 suddenly decide it had a schedule, and was constantly setting the temp down.

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My Nest thermostat was doing something very similar. If you have auto scheduling turned on in the thermostat’s preferences that could be what is making the change. I have to leave my Nest out of auto mode and set the schedules using ST with Routines.


My thermostat doesn’t do schedules. It’s either set it by hand, or controlled via z-wave, with a home/away option. I checked that home/away option, and even that is set to change to 68 in away, so I’m still not sure where the 65 might be coming from.

Wife having hot flashes ?

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I had a similar issue with our Peq Pearl thermonstats that I use with SmartThings. It would reset its temperature to a higher setting at night. I spent quite a bit of time troubleshooting this, and even got support involved, but we could never get to the bottom of it. It was affecting our sleep, because in our case, the thermostats reset itself to a higher temperature at night, and that caused us to not sleep well.

In the end, I wrote a “Thermostat Nanny” smartapp that would monitor the temperature set points and reset them to our required values when in night mode and the set points were reset too high. I haven’t touched the code, nor had issues, since then, probably 18+ months.

Our issue may not be the same as yours, and it may not even be happening for us anymore. If you’re interested, I can post the code, but it’s a band-aid at best. In our case it “solved” our comfort issue, but the engineer in me still sometimes wonder what is going on.

Is your thermostat running on batteries or powered from the A/C system? Is it possible you have power glitches that causes a reset?

My thermostat is powered by the Unit. I had it set at 70 and cut the power, making sure the thermostat was off, and it retained it’s setting of 70 when I turned it back on.

We are buying a new house. The house came with a SwiftAire SA2220 thrmostat. Cool would reset to 85. Warm to 65. We replaced the thermostat with a Braeburn 2220NC thermostat, which is what the re-stickered SwiftAire was. Same problem. Don’t know what to do short of calling a HVAC serviceman.

Thank you so much for posting this! Ours apparently just reset itself to 62. It’s not a smart thermostat, just has the hard to press physical buttons. We have lived here less than 2 years, but it’s never given us any problems. It began getting colder and colder in here, so I went to look and it was set on 62~! No idea where 62 would have come from except perhaps before we purchased the house, while it was vacant? Perhaps this does mean it’s time for a new thermostat. There’s no way either of us accidentally pressed that button long and often enough to set it down from 73 to 62. At least with your post, I know I’m not crazy - just cold :wink: Thank you~! I reset it to 73 and it’s getting warmer in here now.

I got one for y’all! We have a dumb thermostat we keep on 78 in the summer and 68 in the winter. You have to change the thermo stat manually. We never use the auto set change settings. We woke up this morning and it was freezing in the house for summertime? The “Cool” setting was changed to 68? No one touched it? My wife and I and our two cats are the only inhabitants? Anyone? Rick