Heat pump and furnace come at same time

[Wayne&Sam]

This just started to happen: If the thermostat is set on "Auto" or "Furnace" the furnace and the heat pump come on at the same time. I have to check to see if it happens on "Heat Pump" as well.

I've lived with it for a few weeks by turning the breaker for the Heat Pump off so just the furnace will come on.

Anyone else run into this? I'm not sure if it's a thermostat or the electronic controller in the heart pump that is causing the problem.

I'm on warranty, but if it's the thermostat, it would be cheaper to just replace it rather than tow a 5-6 hour round trip to the dealer.

[Wayne&Sam]

I guess no one else had this problem. But in case some further internet surfer does, here's the solution:

The fan setting on the Dometic thermostat has to be set to "Auto" otherwise the fan on the air conditioner will come on with the furnace. I didn't see anything about this in the manual, it took a trip to a local Dometic service center to find out. They said I wasn't the only one who had this problem.

[overlander63]

Originally Posted by Wayne&Sam

I guess no one else had this problem. But in case some further internet surfer does, here's the solution:

The fan setting on the Dometic thermostat has to be set to "Auto" otherwise the fan on the air conditioner will come on with the furnace. I didn't see anything about this in the manual, it took a trip to a local Dometic service center to find out. They said I wasn't the only one who had this problem.

This is a very common thing. Every Dometic newer (digital) thermostat will enable the A/C fan either constantly or when the furnace kicks on, when the fan speed is set to anything other than "auto". This is not only on Airstreams.

[hhendrix]

Originally Posted by overlander63

This is a very common thing. Every Dometic newer (digital) thermostat will enable the A/C fan either constantly or when the furnace kicks on, when the fan speed is set to anything other than "auto". This is not only on Airstreams.

Well thanks to the new improved search function and this thread, I've saved a lot time, trouble, and money. Thanks