AC compressor coming on when heat is selected. Have tried everything

[Michael3337]

Please help.  I can provide pic of old thermostat setup.   

@CoolingWizard 

[sicsacol]

Hi @Michael3337,

Thanks for posting in the community forum. I'm sorry to hear you're going through this with your system and your Nest thermostat. I understand it can be frustrating when your device isn't working as expected. Don't worry, let's work together to get this fixed. To help me with that, I have a few questions:

• What type of Nest thermostat do you have?
• When did the issue start?
• What other strange symptoms have you experienced since the problem started?
• Are there any error messages? If so, what are they exactly?
• What type of HVAC system do you have?
• Does the issue happen on heating only, cooling only, or both?

Please let me know the answers to these questions, and I'll be happy to help you further.

Regards,
Jonathan

[Michael3337]

Great thanks for your help

• What type of Nest thermostat do you have?  4th generation with temp sensor
• When did the issue start?  When i installed it, has not worked correctly
• What other strange symptoms have you experienced since the problem started?   No other just this one
• Are there any error messages? If so, what are they exactly?   No error messages i just went outside and heard the compressor on. And the air coming the the vents was cool
• What type of HVAC system do you have?  Not sure i dont have a heat pump
• Does the issue happen on heating only, cooling only, or both?  I only tried cooling. We are having winter weather here

hope this will help

[sicsacol]

Hi @Michael3337,

Thanks for your reply, and sorry for the delay. I really appreciate the information shared.

To better assist you, please provide a picture of your current wiring configuration. This information will help me see if it's installed correctly.

Any additional details you can provide will be helpful.

Cheers.
Jonathan