Nest Thermostat disconnects from wifi and power when trying to run

[Jtunger]

Good Afternoon,

I just recently attempted to install a google nest thermostat in my home, however, I am having some issues. The old thermostat that I am replacing worked just fine, however, I previously installed a google nest thermostat in another home and loved it.

I have the following wires, Y, W, C, & R. I have properly connected those and went through the set up, connecting the nest to wifi. As the thermostat tries to run the unit, the unit will start and then shut off. The thermostat then shows that it is not connected to wifi and does not have power.

When I check the settings for the thermostat it shows that it has power, all wires are connected and that it has a strong connection with the WiFi.

I have since wired the old thermostat back in and it runs just fine… so any help would be greatly appreciated!

[Patrick_Caezza]

@Jtunger 

Can you post a picture of the original thermostat's wiring if you have it?

If the Nest is still installed, check the voltages 

Nest thermostat information menu 

[Jtunger]

@Patrick_Caezza  Thanks for the response. Here is a picture of the wiring for the old thermostat. I do have the old one wired back up so that I do have AC.

[Patrick_Caezza]

@Jtunger 

If there is enough wire, I suggest that you cut off the exposed copper and strip it back to expose a little over 1/2" of fresh shiny copper.

Do you have a voltage meter? If you do, measure the AC voltage between the blue (C) and Red (R) wires. It should read around 24VAC.

Wire the Nest like this after you turn off the power to the HVAC at the breaker panel.

Yellow - Y to Y

Blue - C to C

Red - R to R

White - W to W