Nest outdoor temp or external temp sensor for dual fuel???

[kevarn123]

I have a heat pump and furnace dual fuel heating system connected via an IO HVAC control board. This control board is connected to an outdoor temperature sensor that independently controls the temperature balance point between heat pump and furnace heating. My question: with a new Nest thermostat that uses wifi for outdoor temperature readings, is the existing outdoor sensor even needed? Any issue with having both outdoor temp methods being enabled at the same time (don't want both HP and furnace coming on at same time)? Should it ultimately be the Nest or the control board that dictates the balance point with this setup? 

[Todbone]

The thermostat wifi should control at what temperature your heat pump shuts off and furnace kicks on. You shouldn't need the OAT sensor connected as well.

[kevarn123]

RESOLVED: Not only did I need to disconnect the outdoor temp sensor, but I then needed to jump those temp sensor terminals for the Nest to take complete control of heat pump heating. 

[EdwardT]

Hi folks,

@Todbone, thanks for the help!

@kevarn123, thanks for reaching out. I'm glad to hear that you were able to figure out the resolution and thanks for sharing the steps that worked for you. Please observe it for now and let us know if anything comes up.

Thanks,

Edward

[Markjosephp]

Hi kevarn123,

I know it has been a while but I wanted to ensure that everything is covered here. How's your thermostat now? Still need our help?

Best regards,

Mark

[Markjosephp]

Hello kevarn123,

I just want to check if you have seen our response posted above. Let us know if you have additional questions, otherwise we'll be locking the thread in 24 hours.

Best regards,

Mark