I replaced my thermostat with a line voltage thermostat. A week or so later it smelled like burning plastic. I shut off the breker and removed it and the one wire nut was actually melted. I had an electrician at my house and asked him to check it out. He felt it was a loose connection and recapped it. It's been about 3 months and it smells like burning plastic again. It seems to me like the wire coming into the thermostat is warmer than the ones going to two 10Ft. Electric baseboard heaters. Any help appreciated. Greg [email protected]

Greyhound,
Can you tell us:
What is the power rating of the heater? There is a nameplate somewhere
With the power of the heater in watts...
What size are the conductors that are connected to the thermostat? #14 awg romex?
What size is the circuit breaker this is connected to?
The more you can us the better the advice...

Loose connections will generate heat, If that 1 conductor is hot, it is a bad connection.
You may need to replace the thermostat if a cgood connection cannot be made, and connect a good clean copper wire, firmly and you should be OK.
You could use a low voltage thermostat and use a contactor so the load of the heater doesn't go through the Thermostat.

"Loose connections generate heat"