Heat Pump question now that cold season has arrived

[NXR]

Thanks for the detailed explanation. They are Atwood units. I'll work through our dealer and pass your detailed information to them so they'll believe me.

Thanks again, and welcome!

Ray

[emm-dee]

Originally Posted by wtroyer01

Hi everyone, my name is Will Troyer and I am the Account manager for Dometic (Atwood) that handles this Forest River Facility. I inadvertently gave Kary the wrong part number below and I would like to clarify that it should be part number 15092 (Not 15080). The previous number I provided is for a Non-Ducted system and wont be the correct part for your 15K ducted Air Command.

I would also like to provide a little background to this subject.

This condition does not always present itself, but it could potentially happen for some people. It really depends on what the temperature is outside Vs what the set-point temp is in the coach.

The way the existing “heat pump mode” software was written was that the fan would shut off when the set-point was satisfied. With the Thermistor located in the air-box, and the air not blowing across it, the software will think that it needs to start again when the air cools off in the AC. Once the fan starts and pulls in the room air, it satisfies the thermistor again and the cycle starts over. This seems to present itself more often where the set-point temperature is easily (or quickly) achieved by the heat pump.
To fix this, we updated the software in the replacement control board so that when the heat pump set-point is satisfied, it will put the fan on its lowest setting so that air will continue to be pulled across the room thermistor. Once the room temp is calling for heat again, the compressor will engage and potentially raise the fan speed (depending on set-point Vs actual). This eliminates all of the “Short cycling” or Off/On nuisance issues, if they are having them. Also this is the same logic that is used on the "Cool" function in the software.

Hopefully this helps you all, and I will pass this post along to our Tech service group!

Can you send the part direct to me so I can do the install or do I have to go through a dealer. If I have to go through a dealership for the work then I’ll just have to live with the way it works now.

[Jan Gerstner.]

Ours did the same thing, once we understood that we actually HAVE one. No idea why. We have a 2014 Forester.

Two things seem to have remedied it:
1. Set the temperature well beyond what you want. For example, if it's cold and you want a coach temp of 70, set 75 or even 80.

2. Your fan. We can select "auto", "hi", and "lo". For a while the HP would work only if we selected "hi". Just this year it has begun working as it should in "auto". Remember, just like your furnace, when the temperature sensor "sees" what you have selected, it will shut off the fan. Hence, setting a temperature well beyond what you want.

[chroniekon]

I have the same question as emm-dee

[firemech2]

Originally Posted by karykatz

Joepa77

My name is Kary Katzenberger and I am the Product Manager for the Forest River Class C Division. I have been in contact with Dometic regarding your heat pump because it isn't operating the way its designed. It sounds like the control board needs to be replaced. If you go to your local dealer they should be able to help. The Dometic part number for the replacement board is #15080. Thank you for purchasing a Forest River product.

Hi kary and fellow forum members we are having issues with our Atwood 1511. We have a 2018 Forester 2421 with the heat pump/furnace. We set the thermostat for heat and put it on Auto (not hi, med or low fan) the furnace puts out heat but the heat pump blows cold air and we cannot shut off fan. We have resorted to flipping the A/C breaker to turn off fan. Also Back at the beginning of the year when we were under warranty our A/C would work properly but again the fan never shuts off. We have it set on auto but after it reaches our desired temp the fan continues to run. The service center told us that is how it is supposed to work. So now we are out of warranty and it appears these issues are related? Thank you all for for your thoughts and help. Please forgive me if I am hijacking this thread, I would be happy to start a new one. Rick

[NXR]

Originally Posted by firemech2

Hi kary and fellow forum members we are having issues with our Atwood 1511. We have a 2018 Forester 2421 with the heat pump/furnace. We set the thermostat for heat and put it on Auto (not hi, med or low fan) the furnace puts out heat but the heat pump blows cold air and we cannot shut off fan. We have resorted to flipping the A/C breaker to turn off fan.

If the temperature difference between where the thermostat is set and the inside temperature is more than three or four degrees (I forget which) then the thermostat automatically turns the propane furnace on to catch up faster.

From the manual:

"When furnace is working as primary heat source in heat mode, pressing FAN button for 5sec to turn the fan off, display will show “FF” until button is released. Pressing FAN button again for 5sec to let the fan continue running, display will show “F0” until button is released."

Also back at the beginning of the year when we were under warranty our A/C would work properly but again the fan never shuts off. We have it set on auto but after it reaches our desired temp the fan continues to run. The service center told us that is how it is supposed to work. So now we are out of warranty and it appears these issues are related? Thank you all for for your thoughts and help. Please forgive me if I am hijacking this thread, I would be happy to start a new one. Rick

Our 2019 AC1511 fans also never turn off in Auto and Cool. Since the temperature sensor is at the roof unit and not the thermostat it makes sort of sense so that there is always air flow needed past the sensor.

What does not make sense to me is why the thermostat temperature sensor is not used 100% of the time like in a house. Then the fan would not need to run and because heat rises.

A Dometic service center told you that or the dealer told you that?

Ray

[firemech2]

From the manual:

"When furnace is working as primary heat source in heat mode, pressing FAN button for 5sec to turn the fan off, display will show “FF” until button is released. Pressing FAN button again for 5sec to let the fan continue running, display will show “F0” until button is released."

It appears the the heat pump fan continues to blow cold air, while the furnace is blowing nice warm air only when the temp is colder than 45 degrees. But why would the Heat Pump fan not turn off. If the temp is over 45 degrees the heat pump works as it should.



Our 2019 AC1511 fans also never turn off in Auto and Cool. Since the temperature sensor is at the roof unit and not the thermostat it makes sort of sense so that there is always air flow needed past the sensor.

What does not make sense to me is why the thermostat temperature sensor is not used 100% of the time like in a house. Then the fan would not need to run and because heat rises.

A Dometic service center told you that or the dealer told you that?

Ray[/QUOTE]
Yes the dealer told us that after consulting with Dometic. Thanks for your input, Rick

[emm-dee]

Good to know there is a fix for this problem. Unfortunately, Dometic customer service will not replace the part under warranty unless I take the unit to a repair facility...or pay $87 for a non-warranty replacement.

I don’t deal with any repair facility or dealer for maintenance. They are usually incompetent or insist on me leaving the rig parked outside for 4-6 weeks before they start a less than one hour job.

That brings up the question....is there a way to disable the heat pump function since it’s basically unusable?

[NXR]

That brings up the question....is there a way to disable the heat pump function since it’s basically unusable?

We have a separate selection for Heat on our thermostat. You don’t?

Ray

[dcheatwood]

Turn off breaker to ac. Then only lp furnace will run.

Originally Posted by emm-dee

Good to know there is a fix for this problem. Unfortunately, Dometic customer service will not replace the part under warranty unless I take the unit to a repair facility...or pay $87 for a non-warranty replacement.

I don’t deal with any repair facility or dealer for maintenance. They are usually incompetent or insist on me leaving the rig parked outside for 4-6 weeks before they start a less than one hour job.

That brings up the question....is there a way to disable the heat pump function since it’s basically unusable?