Nest dumping heat when ac ia kn

[Krmgirn91]

My Nest thermostat has been functioning correctly for a few years in controlling my heat pump. Yesterday, I turned on the AC and left the house. When I returned home, it was blowing only hot air and I got an email from Google that my system was on AC but the house got 8 degrees hotter.  I have not changed a thing from when it was functioning properly.  I assume it’s an issue with the Nest sending the wrong signal to the heat pump.  Does anyone know how to determine if the Nest is functioning properly or not, so I can focus my troubleshooting other parts of the system

[GabrielaG]

Hi @Krmgirn91,

Thanks for reaching out to the Google Nest community. I'm sorry to hear your Nest Thermostat is not working as expected and it was blowing only hot air, but there's no need to worry; I'm happy to help you right now.

To get a better understanding of the situation, please help me out by answering the following questions:

• What type of Nest Thermostat do you have?
• Where did you install your thermostat?
• Do you see error codes on the Nest Thermostat screen?
• Have you tried any troubleshooting steps? If so, can you list them?
• Can you please send a picture of the Nest Learning Thermostat 3rd gen wiring?

Any additional details you can provide will be helpful.

Regards,

Gabriela

[Krmgirn91]

• What type of Nest Thermostat do you have? Second generation
• Where did you install your thermostat? In living area by the stair just on top of furnace with 4 vents nearby
• Do you see error codes on the Nest Thermostat screen?NO error only heat showing ac is running but furnace ia dumping heat i can see temperature up on furnace
• Have you tried any troubleshooting steps? If so, can you list them?yes i did my furnace specialist who install ac did twice.
• Can you please send a picture of the Nest Learning Thermostat 3rd gen wiring? All wiring are correct as per technician and certification

[GabrielaG]

Hi @Krmgirn91,

Thank you for your reply and the information you provided me. I appreciate the time you took to respond to my questions. I'm happy to continue assisting you.

If your system starts to blow warm air when it's in cool mode, changing the settings for the orientation of your heat pump might fix the issue. To change the Heat pump orientation, please follow the steps below:

• • On your thermostat, go to Settings.

• Select Equipment.

• Select Continue > Continue.

• Select Heat Pump.

• 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.

• To make sure that the issue is resolved, test your heating and cooling again.

Let me know how it goes.

Best regards,

Gabriela

[Krmgirn91]

Heat runs proper but mein its in ac mode some time once in week or twice suddenly start dumping heat in ac mode i want to send the pictures to you with wire setting any link 

[Krmgirn91]

 

 

[GabrielaG]

Hi @Krmgirn91,

Thank you for your reply and the information you provided me. I appreciate the time you took to respond to my post. I'm happy to continue assisting you.

Reading the first post, you mention your system is a Heat Pump, but checking the pictures of the wiring you sent me, it seems that you have a conventional system. 

Just to confirm and send you the correct troubleshooting steps, can you please help me out by answering the following questions?

• When you installed the Nest Thermostat, did you set up your system as a heat pump?
• What other strange symptoms have you experienced since the problem started?
• Do you notice any intervals or specific patterns between these strange behaviors?
• Does the issue happen before with heating or cooling only?
• Is this the first time you're activating the AC since the season changed?

Any additional details you can provide will be helpful.

Regards,

Gabriela

[Krmgirn91]

• When you installed the Nest Thermostat, did you set up your system as a heat pump?yes 
• What other strange symptoms have you experienced since the problem started?only this issue when is on suddenly some time heat start dumping
• Do you notice any intervals or specific patterns between these strange behaviors?it happen randomly
• Does the issue happen before with heating or cooling only?only with cooling heating running properly
• Is this the first time you're activating the AC since the season changed? Yes it happen with me last season also