topic Re: Need replacement for nest learning thermostat under warranty in Nest Thermostats

Need replacement for nest learning thermostat under warranty

superdtx — Sat, 30 Apr 2022 19:38:19 GMT

The nest thermostat keeps sending signals to turn on the heater and then immediately cut it off.

I asked the HVAC guy to take a look and confirmed that the equipment is all good if bypassing the nest thermostat.

Also, the nest thermostat can detect Rh but sometimes it cannot.

After talking to google via chat, the nest seemed to be fine after removing the c-wire. So he suggested grounding the c-wire properly.

On the second day, I asked a technician from OnTech to check the c-wire. He said the wiring looked correct but cannot figured out why the nest behaved abnormally. He opened a ticket with Google and suspected it is a compatible issue.

I had another nest learning thermostat on the second floor with the same setup and everything is fine so far.

It is very weird.

Re: Need replacement for nest learning thermostat under warranty

Patrick_Caezza — Fri, 29 Apr 2022 04:10:01 GMT

Do you happen to have a picture of the original thermostat's wiring?

Having both the Rc and Rh wire means your heater and cooling are separate units and there are normally two cables going to the thermostat.

When you connected the Rc and Rh wires, did you make sure you didn't accidentally swap them? The White wire to W1 must be paired with the Rh wire or problems will happen.

Re: Need replacement for nest learning thermostat under warranty

superdtx — Sat, 30 Apr 2022 19:31:22 GMT

Hi @Patrick_Caezza

The wires were set up by a technician from OnTech and worked fine initially.

Talked to google team through the chat that night I posted in the community, and we found that the nest behaved normally after removing the c-wire.

On the second day I asked a technician from OnTech to check the c-wire but still didn't have a solution on it.

Re: Need replacement for nest learning thermostat under warranty

Patrick_Caezza — Sat, 30 Apr 2022 23:06:56 GMT

With a dual transformer system, the C wire has to come from the cooling side and not the heating.

If you pull the front of the Nest off, can you see if two cables are providing the wires? One should have two wires colored red and white. This cable would be coming from the heating side and should only go to the W1 and Rh terminals.

The other cable should have at a minimum four wires colored Red, Green, Yellow, and White. The white wire should not be connected.

Take a look and tell me what you see. If you see something different let me know.

Re: Need replacement for nest learning thermostat under warranty

EdwardT — Mon, 16 May 2022 19:22:36 GMT

Hi folks,

@Patrick_Caezza, thanks for the help!

@superdtx, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

Re: Need replacement for nest learning thermostat under warranty

Ryan_G — Mon, 06 Jun 2022 21:26:30 GMT

Hey everyone,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have.

Best regards,

Ryan

Re: Need replacement for nest learning thermostat under warranty

Ryan_G — Wed, 15 Jun 2022 22:27:11 GMT

Hey there,

Thanks for being here in the Google Nest Community.

I'd like to bump in here and make sure that you’ve seen our response.

Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Have a great day.

Best regards,

Ryan