Nest won’t shut off heater

[EmilyEnnis0875]

We have a single HVAC with 3 thermostats. It is a damper system. Worked fine this summer with AC. Every time I turn the heat on the unit will not turn off when it reaches temp. We have to flip the breaker to get it to stop. Turning off thermostats does nothing. I pulled the face off of all three just now and the unit continued to run. But noticed the orange wire isn’t connected in the top floor or bottom floor but it is in the main floor. 
Unit 1 yellow - y1, green - G, orange - NOT CONNECTED white- w1, blue-C, red-RH

Unit 2 yellow - y1, green - G, orange - OB, white - w2Aux, blue - C, red - RH

unit 3 yellow -y1, green - G, orange - NOT CONNECTED white - w1, blue - C , red - RH 

[RenzJ]

Hi  EmilyEnnis0875,

Thanks for posting here in the Google Nest Community. Let’s look into this. You mention the not-connected wires, we’ll need to check the other side of it to see if it’s connected to your zoning board.

Send us a photo of your zoning board wiring. Also, if I may ask, do you have a multimeter?

We’ll check if there is enough voltage coming from your system since it’s supporting three thermostats at three different locations in your house.

I look forward to your response.

Regards,

Renz