Heat pump operating range

Thanks for all the replies and great info! My heat pumps do indeed switch over to propane heat at some point. After reading all the posts I decided just to use the propane last night. The outside temp was 5.8F this morning, so I am glad I did. Now off to Florida tomorrow.

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.

crawford wrote:
naturist if your heat pump freezes up something is wrong with it. It should go into defrost mode and change back when finished cycle to heat if temp isn't high enough that's when the heater strips kick in to help. Some people think AC and Heat pumps are the same they are not.

If we were talking residential or commercial building heat pumps, I’d agree. RV units not so much.

Ivylog wrote:

crawford wrote:
Some people think AC and Heat pumps are the same they are not.

I do not think they are the same, I know they are the same thing with a reversing valve. Most do not have heat strips and most of those that do, are just AC units that use heat strips for heat...no reverse cycle.

Difference between home units and RV unit. I know home heat pumps have heat strip backups but I've never heard of a RV heat pump having heat strip backup. The gas furnace is the RV heat pump backup.

crawford wrote:
Some people think AC and Heat pumps are the same they are not.

I do not think they are the same, I know they are the same thing with a reversing valve. Most do not have heat strips and most of those that do, are just AC units that use heat strips for heat...no reverse cycle.

crawford wrote:
If your heat pump turns into a furnace were do you think the heat pump get heat to make a furnace ? electric coils were else.

While your Georgetown may not switch to another source of heat (not built in heat strips) when it gets cold enough, most do and usually it’s the propane heater...mine is the diesel AquaHot. I would not double down on something you are misinformed on.

I can not comment on heat pumps used in RVs, but I do know a few things about residential heat pumps, especially what are commonly referred to as "min-split" (two piece; an indoor air handler and outside compressor).

Mini-splits are in a very gray area. Some work well down below 0F, other switch to resistance heat at about 20F-30F. Unless you have documents that say your heat pump will still provide heat a 7F, you are likely going to be relying an electric heat or a propane furnace.

naturist if your heat pump freezes up something is wrong with it. It should go into defrost mode and change back when finished cycle to heat if temp isn't high enough that's when the heater strips kick in to help. Some people think AC and Heat pumps are the same they are not.

crawford wrote:
If your heat pump turns into a furnace were do you think the heat pump get heat to make a furnace ? electric coils were else.

I think what he meant was the heat pumps turns off and the propane furnaces turn on automatically. That's what ours do at about 35 degrees. If it is predicted to get that cold outside, we normally just turn on the propane furnaces instead of the heat pumps before turning in for the night. Not all heat pumps have heat strips.

If your heat pump turns into a furnace were do you think the heat pump get heat to make a furnace ? electric coils were else.