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Heat pump does not start Nest Thermostat

Beenow
Community Member

 Can anyone help me if my wiring is correct on Nest diagram? I can get cool airs but heat does not seem to work  570DDF8D-8E2F-447C-9B50-D3522EC66A6B.jpeg

E725E703-48EB-4B82-B2BB-681D5D4D3CEE.png

1 Recommended Answer

Patrick_Caezza
Platinum Product Expert
Platinum Product Expert

This is my suggested wiring.

White - W1 to W2 (Set as AUX heat)

Yellow - Y2 to Y1

Green - G to G

Red - R to Rc

Orange - O/W2* to OB

Blue - C to C

 

If your system starts to blow cool air when your Nest thermostat is in Heat mode (or if it blows warm air when its in Cool mode), change the settings for orientation of your heat pump.

  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. 
    • If the O option is highlighted, select B.
    • If the B option is highlighted, select O.
  6. Test your heating and cooling again to make sure the issue is resolved.

View Recommended Answer in original post

9 REPLIES 9

MrVacca
Silver Product Expert
Silver Product Expert

Hi @Beenow - I just set mine up last month and it looks like you have the wiring correct. The only thing I can think of is to try moving that yellow wire that you currently have set up in the Y2 over to the Y1 slot above it.  Or just double check to make sure the wires are screwed in tight enough? 

Hope this helps!

 

Bill

Beenow
Community Member

Thanks for your answer @MrVacca  but I currently have yellow line connected to Y1. This morning I noticed that thermostat ignited heat mode correctly but only cool Airs coming out instead of heat. 

MrVacca
Silver Product Expert
Silver Product Expert

From your picture, it looks like the y1 cable is supposed to be right under your orange cable. Did you move your yellow to that one and it still doesn’t work? 

Patrick_Caezza
Platinum Product Expert
Platinum Product Expert

This is my suggested wiring.

White - W1 to W2 (Set as AUX heat)

Yellow - Y2 to Y1

Green - G to G

Red - R to Rc

Orange - O/W2* to OB

Blue - C to C

 

If your system starts to blow cool air when your Nest thermostat is in Heat mode (or if it blows warm air when its in Cool mode), change the settings for orientation of your heat pump.

  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. 
    • If the O option is highlighted, select B.
    • If the B option is highlighted, select O.
  6. Test your heating and cooling again to make sure the issue is resolved.

Hi @Patrick_Caezza 

I think my heat source is AC and not heat pump. So I moved Orange to W2 aux and now heat air coming out. Anything else stays the same, Yellow is at Y1. Do you think I should update wiring as you suggested?

Patrick_Caezza
Platinum Product Expert
Platinum Product Expert

If you do have a conventional system as you think, it would be a 2-stage heat and 1-stage cooling.

The white wire would go to the W1 terminal, and the orange wire would go to the W2 terminal.

Take a look at the terminal block on the control board in the furnace/air handler and see which wire is connected to which terminal. This will confirm or not your thought.

EdwardT
Community Specialist
Community Specialist

Hi folks,

 

@Patrick_Caezza and MrVacca, thanks for the help!

 

@Beenow, how's it going with your Nest Thermostat? Still need our help?

 

Thanks,

Edward

Jhonleanmel
Community Specialist
Community Specialist

Hi everyone,

Chiming in to see if you still need assistance with this. Hope the previous post helped. Let us know if you have additional questions ― we'd love to help.

Best,
Mel

Hi there,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.

Thanks,
Mel