Option to buy Nest 3 mounting base only?

[Cbro]

Is there a way to purchase only the mounting base?  We just had all new wires run to our tstats to provide a common wire and now it seems like all the nests are dead.  Electrician called Google support and it seems the only option is to purchase a whole new tstat.  Seems ridiculous to me.

[virnab]

Cbro,

Thanks for reaching out to the community.

I can see how concerning it is that all of your Nest Learning Thermostats 3rd gen are dead after having new wiring installed. I also understand your worry about being told the only option is to buy new thermostats, and it's completely reasonable that you're looking for a way to purchase just the mounting base. I'd be happy to help.

I can confirm that the mounting base for the Nest Learning Thermostat is not sold separately. The base and the display of the thermostat are designed to work together as a complete unit. However, the fact that all of your thermostats are dead after a wiring change is a significant problem. It might not be the thermostats themselves that are the cause, so let's work together to find an alternative solution.

Before we begin troubleshooting, I'd like to ask you a few questions:

• Could you please provide pictures of the wiring at your thermostats and at the furnace control board?
• Could you or your electrician check the voltage across the R and C wires at the thermostat with a voltmeter?

In the meantime, I recommend that you fully charge the thermostats. You can do this by removing them from their bases and plugging them into a power source using a USB cable.

Please keep me posted.

Best regards,

Virna

[Patrick_Caezza]

@Cbro 

It worked before the new cable was installed, and now it doesn't work after the new cable was installed. Correct?

It sounds more like an install issue than a thermostat issue.

Do you have pictures of how it is currently wired at the thermostat that you can post here?

What about a picture of the terminal block on the control board in the furnace/Air Handler?