Elec. heat v. Gas heat

Hi,

I think the OP only has a heat strip. That will function to well below freezing but will only do 1500 watts of heating. The Dometic thermostat doesn't switch to propane heating.

I added a second "dumb" thermostat which controls only the furnace. It is set to cut in if the temperature sags too much, or if the power goes off. This also allows me use the heat strip and the furnace at the same time.

If the OP has a heat pump, the control board may be sophisticated enough to switch over to the propane furnace if needed.

If someone has added a so called "cheap heat" system it will not automatically switch to propane should the power fail. Nor can you use the electric and the propane simultaneously.

So far, I have always had adequate power to heat 100% electrically. My peak load is about 7100 watts. I've boondocked at -37 C (-34 f) with two 15 amp shore power circuits. My RV is highly modified.

It must be an electric heat pump system, which is basically the air conditioner running in reverse. They are not very effective below 40 degrees. This is probably why it suppliments the heat with propane below that temperature.

Probably the thermostat will control the function. Need to post the make and model number. Otherwise need to RTFM and check the available program options.

A lot will depend on what you actually have. Is yours an AC unit with heat strips (assumed) or actually a Heat Pump? If it has heat strips, I doubt it will auto switch to furnace. If it’s a heat pump will depend on brand, how old, etc.

Mine has a Dometic heat pump and thermostat and it does as you state. When the outside temp falls below a set number, it will auto switch to the furnace. When it warms up outside, it will switch back.

Every MH I had before this one that had heat strips would NOT switch.