Look for a switch marked Coach Heat...this is heat piped in by the chassis heater...worse comes to worse and you don't find it, it has to have a 12v fuse...pull it.
Stuart and Stella Denning
2016 Entegra Aspire 42RBQ
The 3 Bulldogs (Daisy, Sylvie and Stashie)
2018 Equinox Diesel (TOAD)