W1 post on mounting plate always hot

[PeterG3]

I had a W1 wire error code.  Constantly calling for heat.  I figured it was a bad wire from the thermostat to the furnace.  Replaced all the wire between the mounting plate and the furnace. 

When I connect the backing plate to the wire the W1 wire is immediately energized to 24v.  

Tried using jumpers from the R post on the furnace and the W1 post and I get voltage.  The circuit is always closed when R is energized. This is just the backing plate, thermostat not connected. 

I'm guessing the backing circuit board is toast.  There should be no voltage on W1 without the thermostat connected.  

[Jeremyg]

Hi @PeterG3,

Thank you for posting in the community. I am sorry that you are having issues with the W1 wire and the mounting plate is always hot on your Nest thermostat, but no need to worry; help is here.

I need to know a few things about your thermostat in order to provide you with a better resolution.

• When did the issue first occur?
• When was the thermostat installed?
• Did you install the thermostat yourself?
• What is the voltage on the red wire?
• What is the make and model of your HVAC equipment?
• Do you see any specific error code on the thermostat? 

I'll be waiting for your response; any additional details you can provide will be helpful.

Best regards,
Jeremy.