I have electric baseboard heat 120/240v that is transformed down to 24v I believe. I think that there is also a relay in there also. The thermostat has a mercury bubble that makes the connection to turn it on. A couple of weeks ago I got home and the house was around 80 degrees. I tried turning it off but it stayed on. I eventually had to turn the breaker off for about fifteen minutes for it to finally stay off when I flipped the breaker back on. I am assuming it is more of a relay problem than a thermostat problem but I wanted to see what other people thought or if anyone else has had this problem?

Thanks

Yes I would say it would be about a 95% chance it is a relay sticking!