Heat pump to LP automatic change over?

[ThePowells]

Gotta question for those that know.. If I have the heat pump selected for the primary heat, will the LP system kick in at some point if the actual temp falls to a certain point below the set point? This week our predicted temps will be around 50 during the day and mid 30's at night so heat pump will lose it's effectiveness early evening and then tonight I got a message from Progress Energy that the power was out, so no heat pump. I sent SWMBO a text, but evidently she was already asleep but I am waiting to see if she wakes up cold. We had a similar thing one night last week, but we (I) ran out of propane, so no furnace until I got home and changed the bottle so I don't know if it changed over or not. BTW, I don't have the manual yet for the heat pump.

[ThePowells]

I think I found my answer to be that when the ambient temp drops below a certain point that the system will call for the furnace and if it calls for it 3 times in two hours it locks out the heat pump until ambient temp outside reaches about 40 degrees and then unlocks the heat pump. Is this correct?

Rather than deleting my post, I decided to expand on it and leave it as it may help somebody with a future question who may search for the answer.

[boyscout]

I think I found my answer to be that when the ambient temp drops below a certain point that the system will call for the furnace and if it calls for it 3 times in two hours it locks out the heat pump until ambient temp outside reaches about 40 degrees and then unlocks the heat pump. Is this correct? Rather than deleting my post, I decided to expand on it and leave it as it may help somebody with a future question who may search for the answer.

I didn't know about the "three times in two hours" feature but the rest is certainly correct. When temps drop below the low 40s the system doesn't even try the heat pump; turn the thermostat to Heat ELEC and the furnace comes on immediately, ignoring the ELEC instruction.

We haven't found the heat pump to be very comfortable in the 40s and even low 50s anyway. While it comes on and the air that it blows around during long heating cycles is probably warmer than the trailer's ambient air, it feels like cool drafts. We'd get the option again - it's not hard to save the cost of it in un-used propane when it gets cool outside - but anyone thinking that it will supplement as effectively as the heat pump they have at home does will probably be disappointed.

[Bungy]

I may be a little thick but I don’t see the value of a heat pump in an RV, the outside temp will always be lower than the inside.

[LV Naturist]

I may be a little thick but I don’t see the value of a heat pump in an RV, the outside temp will always be lower than the inside.

In order to understand the value of a heat pump in an RV, or at home for that matter, you have to understand how refrigeration works. They are very effective in cooler weather and more efficient than propane heat cost wise. They work well when the outside temps are in the 50's - 60's, but loose effectiveness when the outside temps get into the 40's and below.

John

[JMCFAN]

I use it because I am plugged into a RV site service...their power vs my propane..

[boyscout]

I may be a little thick but I don’t see the value of a heat pump in an RV, the outside temp will always be lower than the inside.

Possibly you're male and not married? Living with women who think 68 degrees is "freezing" means using a heat source when the outside temps get into the sixties and below.

The heat pump option on GD trailers costs (I forget) around a couple of hundred dollars, or roughly ten propane refills, or VERY roughly about 30 days of propane heating in cool spring/fall weather. The electricity to run the heat pump is usually already included in campsite fees, or is usually (not always!) a reasonable extra cost on long-term sites. So a heat pump provides a free or cheaper-than-propane means to have a happy wife and a happy life.

If you don't get that you ARE a little thick!

[Bungy]

Hey, I live in the great white North, I know all about keeping mama warm! My point was it's not very cost effective where power is not free.

[ThePowells]

The Final Answer

While searching for, and printing manuals, I went on an exploration and uncovered this little nugget.....
From the Coleman-Mach manual;

Heating Questions
Q) What is the temperature range for my Heat Pump?
A) The Coleman-Mach heat pump is an effective heat source, as long as outdoor temperatures are above 45°F. Below 45°F, there is not enough heat outside for the system to absorb, and efficiency drops. With a lack of heat, you will run into a freeze up situation that will shut down your compressor, but leave the indoor blower running. We recommend that, if you know your outdoor temperatures are going to be below 45°F, simply heat the application with the LP furnace until the conditions are more ideal for the heat pump.

Q)Why does my furnace come on when I am calling for heat pump?
A) When your thermostat is in the “Electric Heat” mode, if the set temperature is five or more degrees above what it shows as the room temperature; the thermostat will consider this too much of a load for an electric heat source and bring in the furnace to assist. The furnace will continue to run in this case, until the thermostat is satisfied. When the room temperature starts to drop again, the thermostat will try to proceed as normal, with just the electric heat (unless the difference between set point and room temperature reaches five degrees again).
PLEASE NOTE: Some of our thermostats will not run your electric heat and gas heat simultaneously. They will shut down the electric heat in order to bring in the gas heat.
Multiple consecutive calls for the furnace in the “Electric Heat” mode, can cause the thermostat to lock out the electric heat function for approximately two hours, triggering the furnace only when it needs heat. For more information on the Lockout function of the thermostat, click here.

Now I know about the 45 degrees. I was thinking 40. This means I gotta get my propane T in place sooner rather than later.

[sgrol60]

Amazing how inefficient those heat pumps are. The mini split heat pumps I have at home are good for heating down to 5 deg outside temp.