CT100 thermostat keeps turning off

I have had my CT100 installed and have used ST to control it for at least three years with no issues. In the last week the thermostat suddenly started going into off mode at random times. Sometimes it happens once and then operates normally for a few days before doing it again. Today it turned itself off twice. It has happened both when people are present and when the house is in away mode.

I typically use Webcore to control the temperature setpoints. Also, this thermostat only controls my heat. I have a virtual switch that I turn on during heating season that triggers all the other pistons. It is the only pistons that is setup to command the thermostat to turn off. I have not touched the switch since October.

The activity feed for the thermostat does not show that any command was sent. It will just read thermostat off. I have been having some trouble with my Lifx bulbs in Webcore recently, but I am not sure if that is related. Any advice would be greatly appreciated.

Try to press the black reset button and also check the batteries. If you aren’t using batteries check the C-Wire stability. It’s best to add batteries even if you have a C-Wire to improve the stability. If the batteries drain over time then the C-Wire isn’t providing enough juice.

See pic of reset button:

Thanks for the suggestion! The thermostat is hooked to a C-wire, but I also keep batteries in it at all times.

I put in brand new batteries and performed the reset. I also paused all Webcore automations that deal with the thermostat. So far it hasn’t repeated the issue since making these changes. I will start adding the pistons back in slowly just in case there was a programmatic issue at play.

Having the exact same issue.

I’ll put fresh batteries in there but I’m hooked up to the C wire.

This has been stable for years.

Just following up that a reset and new batteries seems to have done the trick. Sort of wish I did one before the other, but its been solid for several days.

Assuming it was the reset that did it considering on on a C-Wire.