Heat Pumps on a Classic 30' 2018

[Airhead2018]

Does anyone know if there is a temperature in which the heat pumps (by themselves, Alde turned off) will not operate? Meaning not come on at all when turned on at Firefly. The outside temp this morning was 33/34 and that also reflected the inside temp and when I tried to turn on one unit I got a click and that was it. Now I'm only connected to 30 amp service so only tried one unit at a time with the same response. I also lowered the temp to be within 5 degrees of temp in the trailer so it wouldn't be calling for the Alde to help out. I have the breaker to the Alde turned off anyway because it is winterized. Now having said all of that I put a heater inside and got the temp up to 63 or so and in the mean time the outside temp got up to 43 or so. I decided to try once more before making a phone call and what do you know it came on. Anyone have this experience? Of course I got no manual for the heat pumps with this unit and Dometic couldn't help me with it either.

[BigSxyWhtGuy]

Yes, below 50 is tough and below 30 is no longer ideal. You are really close to that mark.

[Airhead2018]

I'm not referring to its heating capabilities while running in cold weather, I am talking about the units being held off (will not run) until a certain temp is reached. Be it an outside temp or an inside temp. Like the heat pump at my house will not run below 40 degrees.

[dznf0g]

It's a bit lower that that for my Penguin 13.5k. At about 36 or 37 it won't come on....and if on, switches to furnace.
Still puts out good heat all the way down as well.

[kendrick.l.j]

Hi Air2018, I have a 2017 Classic so mine is a bit different than yours because of how the Firefly interfaces with the Alde. I used mine last year in temps way below 32 and didn’t have a problem with the Alde system. I did try to use the heat pump a couple of times just to see if it would work, it does ok in temps at or around 40 or higher but the Alde is so good and so quite that I never use the heat pump anymore. Sorry this wasn’t more helpful but for most of us with the Alde system there is no reason to bother with the heat pump.

[GMFL]

Originally Posted by dznf0g

It's a bit lower that that for my Penguin 13.5k. At about 36 or 37 it won't come on....and if on, switches to furnace.
Still puts out good heat all the way down as well.

My 23 has a 13.5K and does the same thing. Temps in mid to low 30’s it switches over to furnace

[Airhead2018]

Originally Posted by dznf0g

It's a bit lower that that for my Penguin 13.5k. At about 36 or 37 it won't come on....and if on, switches to furnace.
Still puts out good heat all the way down as well.

Thanks Rich, that is the answer I was looking for!

[Airhead2018]

Also thanks to all for their responses!

[quietguy]

Originally Posted by Airhead2018

Also thanks to all for their responses!

The answer is yes. It will shut off automatically when the outside temp gets too low. It is explained in my owner's manual. I don't have it in front of me so can't give exact numbers but somewhere in the mid 40's the HP goes into alternating heating/defrosting cycles and will no longer keep the trailer at the desired selected temp. A few degrees colder (somewhere around 38-42...again don't have manual in front of me) and it shuts down completely and your only source of heat will be your furnace (or boiler if a newer Classic).

[Nightmare67]

Every heat pump has a “cross-over temp” based on its efficiency, below which, it will be locked out. On my home system, it’s 37.
Basically, that means that below 37, the heat pump is unable to extract enough heat from atmosphere to use effectively.

[fkiehl]

I have a 2018 Classic 33 and the heat pumps will NOT turn on if the outside temperature is below 35, above 35 they work fine.

[Airhead2018]

Originally Posted by Nightmare67

Every heat pump has a “cross-over temp” based on its efficiency, below which, it will be locked out. On my home system, it’s 37.
Basically, that means that below 37, the heat pump is unable to extract enough heat from atmosphere to use effectively.

Not exactly, we have an older heat pump in the house we live in now and it will run until the cows come home. Just saying

[Airhead2018]

Originally Posted by fkiehl

I have a 2018 Classic 33 and the heat pumps will NOT turn on if the outside temperature is below 35, above 35 they work fine.

Thanks, I need to get the model number of the units so I can get a manual. I tried the heat pumps later when the outside temps got up and they worked fine. Had some issues with Firefly/Alde configuration previously and was hoping it was something simple like that.

[mikeinca]

It's interesting that this topic came up because we recently had the same issue with one of the heat pumps on our 2018 30' Classic. What was curious was that at an ambient temp of around 40 degrees the rear unit came on and produced warm air but the front unit just gave a "click" and did not activate. While I know that heat pumps don't work at low temperatures, since one unit functioned and the other didn't I assumed that something must be wrong. But at the dealership they couldn't replicate the problem (of course) and both units performed perfectly. Maybe the temp threshold varies slightly from unit to unit.

[Airhead2018]

Originally Posted by mikeinca

It's interesting that this topic came up because we recently had the same issue with one of the heat pumps on our 2018 30' Classic. What was curious was that at an ambient temp of around 40 degrees the rear unit came on and produced warm air but the front unit just gave a "click" and did not activate. While I know that heat pumps don't work at low temperatures, since one unit functioned and the other didn't I assumed that something must be wrong. But at the dealership they couldn't replicate the problem (of course) and both units performed perfectly. Maybe the temp threshold varies slightly from unit to unit.

Sounds like the outdoor temperature sensor might be a little off on that unit, where ever that might be. Everything works at the dealer, funny how that works.

[james.mileur]

My 17 Classic dometic thermostat manual says, 30 degrees and above for heat pump to work. No run time to validate how low it will go, Alde does such a good job.

[mojoe7009]

Originally Posted by james.mileur

My 17 Classic dometic thermostat manual says, 30 degrees and above for heat pump to work. No run time to validate how low it will go, Alde does such a good job.

I agree with James. Alde does such a great job I can only imagine using my heat pumps if the Alde system completely failed. We use the night timer function every night. We set the system to not go above 58 from 9:30 pm until 5:30 am then it is set to 65. By the time we get up at 6:30 the trailer is nice and warm. Just set once, turn on and forget it.

[Airhead2018]

Alde system is winterized, otherwise I would be using it. In any case I want to know if all systems are operational. Thanks for the info on the Dometic thermostat which I don't have, but will look up just for info purpose. Thanks again!!