Quote Originally Posted by spyderrobotics View Post
This very well could be. Proportional thermostats usually work fine with GFI's. I've only come across one or two cases where there was an issue. If I remember right the person replaced the GFI with a new one of the same model and then it was fine. So there may be some tolerance differences. If you weren't already I would use a surge protector with a 2000+ joule rating in between the thermostat and wall outlet. The protectors have a mov cap that I suspect works both ways and may keep the relay arc from tripping the GFI.
Thanks, I didn't even think of a surge protector. That's a good idea.