Nest Gen 4 not cooling, heating on cool, heat pump

[clpost]

Installed a gen 4 Nest to replace my Emerson thermostat for a heat pump (which is brand new). It only runs warm air when set to cool.

Original wiring:

RH - red

O/B - orange

Y - yellow

G - green

W/E - white

C- black

Y2* - blue

On the Google Home setup:

Y1 - yellow

G - green

OB - orange

Rh - red

Y2 -blue

C- black

W1 - white (also tried white on W2aux)

Thank you in advance for any advice!

[GabrielaG]

Hi @clpost,

Thanks for reaching out to the community. I'm sorry to hear that your Nest Learning Thermostat 4th gen is only running warm air when you set it to cool. No need to worry; I'd be happy to provide some guidance.

To get a better understanding of the situation, I'd like to ask you a few questions and send you some troubleshooting steps: 

• When did the issue start?
• When was the last maintenance service and cleaning?
• Is this the first time you’re calling for cooling this year? If yes, did the heating work without issues in the winter?
• Do you see a power error code on your Nest Learning Thermostat 4th gen?

Any additional details you can provide will be helpful.

Regards,

Gabriela

[clpost]

Hi Gabriela! Thank you so much for your response! 

I just bought the Nest 4 gen a few days ago to replace the existing thermostat for my heat pump. The original thermostat works fine and had been cooling my house. 

I had Nest thermostats at my prior 2 houses, and they worked great, but the units were conventional instead of heat pumps. 

My new house is a new construction, so maintenance will be in August of this year.

I didn't receive any error codes on the Nest.

I really appreciate you for helping!

Carrie

[GabrielaG · Accepted solution]

Hi @clpost,

Thank you for your reply. I appreciate the information you provided me about your Nest Learning Thermostat (4th Gen) and your Heat Pump system. I'm happy to continue assisting you.

I recommend the following troubleshooting steps:

• Try to disconnect the Y2 wire from the Nest Learning Thermostat (4th Gen) wiring.
• Do a Factory Reset on your Nest Learning Thermostat (4th Gen).
• Remove your Nest Learning Thermostat (4th Gen) from the Google Home app.
• Set up your Nest Learning Thermostat (4th Gen) back in the Google Home app without the Y2 wire configuration.

Feel free to keep us posted if you have more questions.

Best regards,

Gabriela

[clpost]

Hi - 

I apologize for the delay in responding to you. I had to go out of town for a family emergency.  But I followed your instructions, and the Nest works perfectly! Thank you very much for your help!

[GabrielaG]

Hi @clpost,

Thanks for your reply. I appreciate you taking the time to do the troubleshooting steps. I'm glad to hear your Nest Learning Thermostat (4th Gen) is working now.

Feel free to keep us posted if you have more questions.

Best regards,

Gabriela