Heat pump operating range

There are basically 2 brands of RV HP's Coleman(RVP) and Dometic. BOTH operate within a few degrees of each other. About 36 to 40 degrees ambient, the HP will shut down and go to the other HEAT source in the RV. The LP furnace or a Aqua Hot type system. IF it is BELOW 35-40 degrees and you attempt to turn the HP's ON, they will not come on and default to your alternative Heat Source. Once the Ambient rises above 40 degrees, the alternate Heat Source will stop and your HP's will do the job. Now for the RVP/Coleman HP parameters ABOVE 40 degrees. Dometics do not have this feature. If you set the Warm temp MORE than 5 degrees above the interior temp, the HP's will NOT come on but your Alternate Heat source will. Once the Interior temp is within that 5 degrees the alternate heat source turns off and the HP's will continue to heat until the set temp is satisfied. Doug

PS. an AC and HP are the same unit. The HP just has a reversing valve to reverse the flow of coolant with the appropriate electronic control board to accomplish that. RV HP's DO NOT have a Heat coil for supplemental heating in freezing temps. Residentials do.