Opps, my bad. Sorry about that.

Okay, here's my opinion. I believe you are most likely experiencing a voltage/current surge on the electric circuit (120vac wall outlet). This is the most obvious thing I can see that would cause your recurring problem. I would buy a decent surge protector and plug your thermostat directly into that.

There is one other possibility, but you would need an electrician to check the circuit.

Good Luck!
Jim Smith