CT100 Thermostat Mode set to "Off" in the middle of the night

This has happened twice in the past two weeks and I can’t figure out why. In the history of the device, it just says “Mode Off” and stops heating.

I check the routines tab for the thermostat and it says “No Routines include this device.” And that’s correct. I don’t directly update it at all except in one of 5 scenes.

I have checked all 5 scenes and not one of them changes the thermostat mode. They only change the temperature.

It said it had 30% battery but just in case I replaced the batteries this morning.

Any ideas how to troubleshoot who or what triggered this mode change at 5:56 am this morning?

Might be a long shot, but by chance did you possibly agree to something w your utility company that allows them to mess with your usage? My utility offered something that sounded good, and rewarded me with a rebate…. But I found it to be a super pain, because they’d shut me off with a frequency, calling it “peak time conservation”

Our heat is oil so there’s no peak time for that… but also, I don’t think the electric company could gain access to my thermostat without my granting explicit API access, which I definitely have not done.

Do you use Alexa? If so, you might verify there are no routines or hunches that include your thermostat.

Change the batteries.

Common issue with this thermostat, when the C-Wire cuts out (which happens with the HVAC circuit detects overheat when in heating mode - this is normal - or when it detects water during cooling), the CT-xxx models reset back to Off. Putting in a fresh set of batteries will provide the power to keep itself running with the C-Wire cuts out.

If this fixes the issue then you may also want you to look into why your C-Wire is cutting out, if it’s normal or not.

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Old house, no C-Wire. However battery reported 30% so I replaced them 2 days ago (when I made the OP). So far so good. I’ll update if this doesn’t fix it.