Atwood A/C with heatpump operation question

You will need to contac Atwood. I have 35 years as a RV Tech and have NOT seen the Atwood on any of the RV's we service. Dometic just bought out Atwood and it will be interesting to see if they continue the Atwood refers and AC/HP brand. When you state 2 fans. RVP also has the 2 fan system. 1. Small fan for the Condensor and the other normal size fan for the inside whole has air. BOTH operate continuously when the compressor is ON. If the compressor cycles OFF, then the condenser fan shuts off also. 2. So, if the upper condenser fan is the fan that starts and stops, then I would say that is NOT normal unless the compressor is also stopping and starting at the same rate as the fan, which IMO is not normal also. Doug

PS. AMAZING WHAT YOU FIND WHEN YOU READ THE OPERATOR MANUAL:D

below from the manual

After the delay, the compressor will start. Usually the fan will stop and will not re-energize until the heat exchanger has warmed and then the fan will start to blow warm air.
- The unit will heat in the heat pump mode in ambient temperatures above approx. 45°F. The furnace will automatically engage at ambient temperatures below approx. 45°F

The fan might be sampling the room air temperature?

That is my only guess.

I have always thought it beneficial to run the fan constantly (outdoor fan really) on a heat pump to thaw out any frost that might be on the outside coil while the compressor is off, and not heating.

Say it is 45F outside, the heat pump is running, and the outside coil can reach say 30F or 27F to collect heat. Ice or frost can develop on the outside coil. It will quickly thaw out and turn to water once the compressor is off, IF you keep blowing the outside air at 45F across the outside coil.

Also on the heat pump (PTAC through the wall heat pumps at my work) units, I have seen ice build up on the outside coil, to the point that the outside fan is brushing against the ice and causing it to sound like it is going to explode! I take out the units, and replace them with a clean one, and let them thaw out in the maintenance shop. Once thawed out, they are ready to go back into another room. Just leaving the fan run (before the ice got thick) would have thawed it out, and prevented that problem.

However it seems like in your case, turning on the thermostat to 'fan on' will only turn on the inside fan, and not both, so you are out of luck, unless Atwood made a provision to leave the outside fan running while in the heat pump mode, and it is over 40F outside, and the coil sensor is between 20F and 35F. So if you hear just the outside fan running, the Atwood engineers are thinking! like me!

Have fun camping!

Fred.

Thanks guys,
It is the inside fan that is coming on and off.
It may be just sampling the air temp. To determine if heat is required.
It is the first time I have needed the heat function.
Will call manf.

Dennis37 wrote:
Thanks guys,
It is the inside fan that is coming on and off.
It may be just sampling the air temp. To determine if heat is required.
It is the first time I have needed the heat function.
Will call manf.

According to my post with the actual Atwood operation instructions, your HP is doing as designed. Doug

dougrainer wrote:

Dennis37 wrote:
Thanks guys,
It is the inside fan that is coming on and off.
It may be just sampling the air temp. To determine if heat is required.
It is the first time I have needed the heat function.
Will call manf.

According to my post with the actual Atwood operation instructions, your HP is doing as designed. Doug

Didn't read the manual OR your post.

Pirate wrote:

dougrainer wrote:

Dennis37 wrote:
Thanks guys,
It is the inside fan that is coming on and off.
It may be just sampling the air temp. To determine if heat is required.
It is the first time I have needed the heat function.
Will call manf.

According to my post with the actual Atwood operation instructions, your HP is doing as designed. Doug

Didn't read the manual OR your post.

Yes, I know. After over 10 years on these forums, that is the norm. I give ACCURATE info or ask for model numbers and the OP continues his asking for help and NEVER reads and responds to my posts that will actually help him. But will respond to nonsense from other posters. Doug