One Thermostat Controls Other in Error

[Matt99]

Hi. We have had two Nest E’s in our house for several years, one in the living room and one in the bedroom on one floor. Heat is generated through a Biasi B10 boiler and we have baseboard radiators. It is a heating only system. 

When installed, both were wired the same way—white wire in W1 and red wire in R. There is a green wire visible in each but it is not connected to the G terminal. 

The two thermostats are, of course, supposed to work independently of each other as zones so that, for example, the living room E could be set at 68 degrees and the bedroom E at 60. However, in practice, the bedroom E seems to be controlled by whatever the temperature setting for the living room E is at. In this example, while the living room E will go to 68, the bedroom E will soar past 60 and end up at 68. I did test this by turning off the living room E and the bedroom E achieved and maintained the temperature it was set at.  I am assuming that wiring might be an issue?

I would appreciate any assistance on how to get these two Nest E to finally operate independently of one another. 

[Markjosephp]

Hello Matt99,

Thanks for reaching out and providing detailed information about the issue you are experiencing with your Nest Thermostat E. I appreciate your thorough description of the setup and the observed behavior.

Based on your description, it is indeed possible that the wiring configuration could be contributing to the problem. Here are a few steps you can take to investigate and potentially resolve the issue:

1. Make sure the white wire is securely connected to the W1 terminal on both thermostats.
2. Verify that the red wire is correctly placed in the R terminal for both thermostats.
3. Even though the green wire is not currently connected to the G terminal, you may want to check if it's needed for your specific system. Refer to your HVAC system control board.
4. Double-check the settings on both thermostats to ensure they are configured as separate heating zones. Verify that each thermostat is set to control the desired area independently.
5. If the issue persists, you may want to try resetting both thermostats and reconfiguring them. This can sometimes resolve software-related glitches.

Let us know how it goes.

Best regards,
Mark