thermastat set to electric heat, but runs off of propane

If there is more than a three degree difference between actual temperature and what you have set on thermostat, gas furnace will come on to bring it up to desired temperature.

35 is too cold for a heat pump so the auxiliary heat kicks in.

My heat pump will not work when less than 35 degrees outside . Heat pump is a heat transfer pump , no heat outside , no heat inside .

We always supplement the heat with OIL-FILLED heaters in our setup. Especially when setup at the camp grounds. Always seemed better to use the camp ground electric verses our propane. We just run a HD extenson cord out to the pedestal and plug into their 20AMP SERVICE...

Roy Ken

Had the same situation, but my RV fixer explained that the system is designed to work that way. Depends on outside temperature.

GM

The Coleman-Mach thermostat for my heat pump switches to the furnace under certain conditions:

1. The difference between temperature at thermostat and target temperature set is too great. I don't remember the maximum difference, it is in the manual and manual in in the RV at storage.

2. A temperature sensor in the heat pump says the outside temperature is too low for efficient operation. I don't know whether the heat pump refuses to switch the reversing valve and communicates that to the thermostat, or if the thermostat gets the reading and makes the decision for "emergency heat" which is how it works at home.

3. The heat pump will run for a long time, in excess of an hour, without coming up to target. Then the furnace comes on too. Next cycle will be furnace only. I don't know whether this is a distinct program, or one of the first two mechanism operating.

If I am expecting temperatures close to freezing, I'll manually switch to the furnace, the heat pump does nothing for heating my utility compartment.

Any other ideas are appreciated.

Maybe about 35 degrees outside....looks like the thermostat kicks to 2nd stage heating when Electric heater can not sufficiently heat to thermostat setting.

I think that's the way it's programmed to run?? At least that's how my home heat pump works when it's too cold for it to run efficiently... ;) Except mine switches to 100% electric heat because I don't have any other form of fuel for it to burn, but at least when it does that, it actually HEATS... When it's too cold for the HP to work, all it's doing is wasting energy and running for nothing..

Good luck with it!

Mitch

Maybe about 35 degrees outside....looks like the thermostat kicks to 2nd stage heating when Electric heater can not sufficiently heat to thermostat setting.

Any other ideas are appreciated.

More info would be helpful, but most heatpumps will only operate above 35 to 40 degrees with most around 38.
Colder than that, the gas furnace will come on.

dnulnoj wrote:
It should run off of heat pump since I am plugged in, but it is running off the propane furnace I guess

Maybe there is a lower temp limit that kicks over to propane.
How cold is it? Have you tried in the heat of the day?

Does the thermostat have a model number?