No heat using nest learning 3rd gen with heat pump

dnnm16
Community Member

I have an electric heat pump system. It worked fine with the original thermostat. I switched over to  nest learning third generation and it's only blowing out cool air. Attached are two pics of my original wiring and my nest wiring. I can't get my heat to turn on. I switch B to O for heat pump setting based on troubleshooting recommendations. I've been looking through all the forums but no answer. I'm not sure if it's because of the heat pump or a compatibility issue. 

Screenshot_20220509-001959_Nest.jpg

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8 REPLIES 8

Patrick_Caezza
Gold Product Expert
Gold Product Expert

Your system uses the B option for the changeover valve and you need to change that in the Nest.

  1. On your thermostat, go to Settings.
  2. Select Equipment.
  3. Select Continue > Continue.
  4. Select Heat Pump.
  5. The Nest Thermostat defaults to an O setting for heat pumps. 
    • Select B.
  6. To make sure the issue is resolved, test your heating and cooling again.

So, I started out in B and switched to O after reading it on the troubleshooting forum. However, it's back to B again with no changes. 

Maybe the wiring at the terminal block on the control board in the furnace/air handler is wired a little differently. Take a look there and see if the wire labels match up, post a picture if you will.

Ryan_G
Community Specialist
Community Specialist

Hi dnnm16,

 

Thanks for reaching out here in the community.

 

I'd like to jump in here and check if you've seen Patrick_Caezza's response. If you have further questions, let us know by replying to this thread.

 

Best regards,

Ryan

dnnm16
Community Member

I havent looked at my furnace yet. I will look at it next week when I'm able to access it. 

Ryan_G
Community Specialist
Community Specialist

Hi dnnm16,

 

Thanks for your reply and I am sorry for the delay.

 

I am looking forward for your next reply once you've checked the main board from the furnace.

 

Best, 
Ryan

Ryan_G
Community Specialist
Community Specialist

Hey dnnm16,

 

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

 

Best regards,

Ryan


 

MelbaDT
Community Specialist
Community Specialist

Hi, 

 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.

 

Best, 

Melba