Heat comes on when ac is turned on

[Katie75]

• Installed my goggle nest but when the ac comes on so does the heat.  Heat stays on and will only cut off when I turn the system off.  We have been trying to figure out if is compatible with the wiring or do I need to try a differnet nest.

[Katie75]

It is a nest thermostat pro

[humbertogarcia]

Hi Katie75,

Thanks for posting in the community! I understand that your heating system is activating with your AC and then turning off until you completely power down the system. I can only imagine how confusing and uncomfortable that must be. I'd be absolutely happy to help you figure out what's going on and verify if your system is fully compatible.

To help me get started and work toward a solution, please provide the following details:

• What is the specific model of your Nest thermostat? You can find guidance on how to identify it here: How to tell which Nest thermostat you have.

• When did the issue start?

• Are there any error messages displayed on your thermostat?

• What type of HVAC system do you have (e.g., furnace, heat pump, boiler)?

• Have there been any recent changes or upgrades to your HVAC system?

• When was the Nest thermostat installed?

Additionally, clear pictures of your wiring would be a huge help:

• If possible, please provide a clear picture of your previous thermostat's wiring.

• A clear picture of your current Nest thermostat's wiring, showing the wires connected to the terminals on the Nest base.

Once I have this information, we can work together to diagnose the issue and get your system running smoothly and comfortably again. I look forward to your update.

Regards,

Humberto