Heat pump issue

[Gordon66]

Replaced both A/C Heat pumps this summer. A/C works fine. Rear heat pump switches to aux heat at around 31*F. Front unit switches at 50*F. Anybody know if and how this setting can be lowered? Manual states they should switch around 30*F. That tells me the rear one is set correctly.

[nodine]

Originally Posted by Gordon66

Replaced both A/C Heat pumps this summer. A/C works fine. Rear heat pump switches to aux heat at around 31*F. Front unit switches at 50*F. Anybody know if and how this setting can be lowered? Manual states they should switch around 30*F. That tells me the rear one is set correctly.

Sorry Gordon but I don't know how to make the adjustment. I would call the manufacturer or locate a service manual.

Bob

[Gordon66]

Received this message from Dometic Customer Service:

It sounds like the outdoor temp sensor (thermistor) is out of range.
Both units should run the heat pump down to about 32 degrees F and then switch to aux heat.
Please have your service center test the thermistor for proper resistance.
We appreciate this opportunity to address your situation, and hope all your future travels are trouble free. Please do not hesitate to contact us any time, to order parts or if we can be of assistance.

Customer Support Center
800 544 4881
edometic.com
Dometic Corp

So when it warms up here I'll check the resistance on the thermistor and go from there.

[nodine]

Originally Posted by Gordon66

Received this message from Dometic Customer Service:

It sounds like the outdoor temp sensor (thermistor) is out of range.
Both units should run the heat pump down to about 32 degrees F and then switch to aux heat.
Please have your service center test the thermistor for proper resistance.
We appreciate this opportunity to address your situation, and hope all your future travels are trouble free. Please do not hesitate to contact us any time, to order parts or if we can be of assistance.

Customer Support Center
800 544 4881
edometic.com
Dometic Corp

So when it warms up here I'll check the resistance on the thermistor and go from there.

Thanks for the feedback Gordon. That certainly seems like it would be a likely suspect since both units were new and you just stated using them in heat pump mode. The thermistor was probably out of tolerance from the factory.

Bob