topic No Power to Thermostat in Nest Thermostats

No Power to Thermostat

Mikes1967Nova — Sun, 02 Jan 2022 19:10:08 GMT

I wired up my Nest Thermostat as instruction state but when I attach the thermostat there is no power. What am I doing wrong?

Re: No Power to Thermostat

johnCNA — Mon, 03 Jan 2022 02:33:38 GMT

Did you power off your furnace while installing the Nest? Do you have too much bare wires showing inside the wiring terminal plate? In addition to a main breaker for the furnace, most furnace control boards have an automotive style fuse on the control board itself. If you accidentally shorted something during setup, the automotive fuse on the control board is what will blow, not the main breaker.

Re: No Power to Thermostat

DC122 — Tue, 04 Jan 2022 21:30:17 GMT

John, I have the same problem where there seems to be no power going into the unit itself but the thermostat works thru the app. I am able to control the temp but actually see it displayed on the unit. If I shorted something out by accident during installation, is there anything I can do to get that going again?

Re: No Power to Thermostat

johnCNA — Tue, 04 Jan 2022 22:35:38 GMT

I'm having trouble visualizing what you're saying. How are you deciding that there is no power?

You're able to use your phone to adjust the temp and that shows on the Nest screen display? And does your furnace respond and start heating if you turn up the temp on the app?

Re: No Power to Thermostat

DC122 — Tue, 04 Jan 2022 22:55:24 GMT

I guess a clearer thing to say is there seems to be nothing powering up the display to show a reading. I can control everything from the app but I can't visually see it being displayed.

Re: No Power to Thermostat

johnCNA — Tue, 04 Jan 2022 23:11:46 GMT

Sounds like a defective screen, if it's otherwise responding via WiFi and controlling the furnace via the app.

You might try resetting it by pressing in on the screen and holding for 10 seconds to see if it will reboot.

I don't suspect low battery or low power if it's connecting via WiFi. But I guess you could try charging it for a couple hours with a phone charger. Uses a standard micro-USB cable into the back of the unit.

Re: No Power to Thermostat

DC122 — Tue, 04 Jan 2022 23:16:36 GMT

I have a newer nest so they seem to have gotten rid of the micro USB charging. I don't see a reset button anywhere as well and I think the only actual way to reset it is thru the display menu which is my problem altogether. I can hear and feel myself scrolling thru the menu items from the small touch area to the right of the unit though

Re: No Power to Thermostat

johnCNA — Tue, 04 Jan 2022 23:26:42 GMT

Mine is the newest Learning 3rd Gen but I know the older ones have a charging port too. Pull it off the wall and look at the back. My USB port is right above the "G".

To reset it, I press in on the screen until I clicks and hold for 10 seconds. The tiny LED at the top of the screen blinks while it's rebooting.

Re: No Power to Thermostat

DC122 — Tue, 04 Jan 2022 23:32:05 GMT

Yea mine is strictly battery in the back no USB port. Also no clicking functionality. I don't know if they wanted it more minimalistic overall but seems to be a downgrade from other versions of the nest tstat

Re: No Power to Thermostat

johnCNA — Tue, 04 Jan 2022 23:38:24 GMT

Well, if it's still under warranty, time to contact Google support for a replacement. Or buy a new one if it's not.

Re: No Power to Thermostat

Xinyuwang — Tue, 20 Sep 2022 16:50:08 GMT

John, I have same problem with power issue, I checked wires, but still show no power.

Thanks,

Cynthia