Nest thermostat wiring

[StuR]

My existing heating and cooling system thermostat has a jumper between RC and RH

The nest installation instructions now indicate that the thermostat is not compatible

Any ideas

[EdwardT]

Hi StuR,

Thanks for reaching out. I'd love to know more about this and I have a few questions:

• What type of Nest Thermostat do you have?
• How is your current thermostat wired?
• What type of HVAC system do you have?

Looking forward to your response.

Thanks,

Edward

[StuR]

Hello Edward,

I have a forced air, natural gas boiler and a/c. (Carrier). I attached photos of the wiring of my existing thermostat plus photos of the Nest and the label on the box.

The problem that I was concerned about was that the existing thermostat has a jumper between RC and RH (where the red wire is connected).

I contacted my heating / cooling technician and he said that the jumper is not needed.

I then connected all the remaining wires to the Nest thermostat (G Y W R) and turned the system on. Everything works correctly.

Thanks for your reply. If you need any other info send me a message.

StuR

[EdwardT]

Hi StuR,

Thanks for the response. The type of Nest Thermostat that you have requires a C wire. It's possible that that's the reason why you're getting a message saying that it's not compatible. Just to clarify, is it working fine right now?

Thanks,

Edward

[StuR]

The Nest thermostat is working correctly.   (I have not checked if the air conditioner will work since I have the outside heat exchanger covered for the winter.)  I don't expect a problem because my heating / cooling tech says it will be fine.

[EdwardT]

Hi StuR,

Thanks for the update. I'm glad to hear that it's working fine now. I will be locking this thread in 24 hours. Please feel free to create a new thread should you have some more questions or concerns in the near future and we'll be more than glad to help.

Thanks,

Edward