CT100 Plus - Temperature Settings Shifting

tl;dr - I’ve been using CT100 and CT100 Plus thermostats for years. Starting a few weeks ago I started seeing my heat temperature settings shifting up by .2 to .5 degrees. I set the heat setpoint to 65, and it changes fine. Then within a few seconds it shifts to 65.2. Or 65.5. I have 4 of these thermostats across two different hubs, and they all started doing this recently.

Why does that matter? Because these thermostats kick in emergency heat + stage 2 heating after a > 2 temperature differential of actual vs setpoint. I have a number of routines to gradually heat my homes before I arrive, using only the heat pump (takes hours but saves $$). Those routines break when that extra increase in the setpoint triggers the heating strips. e.g. the 10k heating strips fire up immediately.

I HATE it when devices that work for years suddenly stop working :frowning: . Any insights would be appreciated.

See this post.

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