I have a duel fuel set up which has been working fine. All of a sudden yesterday the lockout doesn’t work and both the heat pump and the furnace are firing at the same time. The thermostat controlling the change over is the Vision Pro. I know you going to tell me I should call the installer back but when someone says they can install a duel fuel set up and I end up reading the instructions and explaining how to set up the thermostat I lose all trust. I have even reset the VP and reloaded all the settings but that didn't fix anything.
Is there any reason for it to work and then to just get all flakey? I am about ready to go find someone who can just hardwire it.