Nest shuts AC off and immediately restarts

[Caelis]

@Patrick 

I was reading a post this morning and it described my Nest issue pretty close. I have had Nest for four years now. I loved it the first two years. Like the post I read, we had a very temperate April / May where we didn’t need to run the AC at all, and it died. A post said to plug the Nest USB into the correct voltage and it would recharge the battery, which it did. I have had that issue since. That June we started running AC again, now the Nest starts the AC, runs fine for a while, and then starts shutting the AC down / starting it back up again within 3-5 seconds. I installed and repaired ACs in my youth and I know it’s hard on the compressor to start without equalizing. I contacted Google and went through hours of testing. Everything was as it should be. I kept telling the tech that Google needs to code a timeout between restarts. My opinion was that the thermostat reaches set temp, shuts down but since the temp is barely at the set temp, it restarts. I don’t have a C wire. I thought about buying a doorbell transformer with the required voltage and running a C wire. If I do this, one pole goes to the C terminal on the Nest, where does the other pole go to complete the circuit? Thanks for any help.

Caelis

[Markjosephp]

Hello Caelis,

Thanks for reaching out to the Google Nest Community Forum. I'd love to know more about this.

This is most likely a power-related issue that also caused your Nest Thermostat to drain its battery. A few questions: did you notice any wiring reports in its settings? If so, what's the message code? Have you checked if the air filter is dirty and needs to be changed? Also, please gather your thermostat's power readouts in its Technical Info settings.

I'll look forward to your response.

Regards,
Mark

[Caelis1162]

Thanks Mark. About this time last year I called Nest Support and she spent an hour going through everything and couldn’t identify any issue. It absolutely drives me crazy when the AC starts up immediately. How do I add the C wire? I was going to get a door bell transformer with the correct voltage and wire it to the Nest. One pole goes to C, where does the other pole go? I want to eliminate voltage from the equation. I think it is a simple coding fix.

Thanks, Caelis

[Markjosephp]

Hi Caelis,

I'm sorry for the late response. Adding a 24 Volt transformer or C-wire adapter to the thermostat is not suggested as it doesn't usually last, but it helps to provide power to it. You may want to consider this article about the Nest Power Connector with an installation guide on how to install it in your HVAC system.

Let me know if you have more questions.

Regards,
Mark

[Jenelyn_O]

Hi there,

Checking if you still need help. Please let me know, as I'll be willing to assist you further. 

I appreciate the help, Mark.

Best,

Jenelyn

[Caelis]

I would love some help!

[Jenelyn_O]

Hey Caelis,

I'm sorry for the late response. You mentioned above that you called our support team. I'd like to take a closer look at your case. Could you please provide your case ID? 

Thanks,

Jenelyn

[Caelis]

I was reading a post this morning and it described my Nest issue pretty close. I have had Nest for four years now. I loved it the first two years. Like the post I read, we had a very temperate April / May where we didn’t need to run the AC at all, and it died. A post said to plug the Nest USB into the correct voltage and it would recharge the battery, which it did. I haven’t had that issue since. That June we started running AC again, now the Nest starts the AC, runs fine for a while, and then starts shutting the AC down / starting it back up again within 3-5 seconds. I installed and repaired ACs in my youth and I know it’s hard on the compressor to start without equalizing. I contacted Google and went through hours of testing. Everything was as it should be. I kept telling the tech that Google needs to code a timeout between restarts. My opinion was that the thermostat reaches set temp, shuts down but since the temp is barely at the set temp, it restarts. I don’t have a C wire. I thought about buying a doorbell transformer with the required voltage and running a C wire. If I do this, one pole goes to the C terminal on the Nest, where does the other pole go to complete the circuit? Thanks for any help.

[Markjosephp]

Hello Caelis,

I've duplicated your thread in the main one here. You’ll receive all updates on this issue on the main thread, and we recommend updating and checking this thread when needed.

Regards,

Mark