Nest turning AC off, starting again within 5 seconds

[Mckeester31]

Hello. My Nest Learning Thermostat has worked great nearly 1.5 years. We had a very temperate April / May where we didn’t need to run the AC at all, kept windows open. In 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. Earlier this week I observed it doing this multiple times in a 10-15 second span. 

does this if I set the Nest to the thermostat itself, or one of the sensors. Also tried moving the room sensors around. Same problem. Help! This will wear out our new compressor. 

fYi we met all compatibility requirements when setting up the nest. However we do not have a “C wire”. 

[Patrick_Caezza]

Are you receiving any error messages?

How is the Nest wired?

[Mckeester31]

No error messages. We have Y1, G, W1, and Rh wires. AC compressor, forced air furnace, fan, power. 

[Patrick_Caezza]

Not having a C wire could be the problem. I always suggest installing one just because of this type of problem.

Look and see if you have a spare wire and if you do, you can use it to create a C wire.

[EdwardT]

Hi folks,

@Patrick, thanks for the help!

@Mckeester31, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

[Raj072283]

I am having the same issue. Only happens on my upstairs Nest thermostat/unit.

My separate downstairs Nest/unit works normally. 

I have Y, G, W, and Rc wires.

Any solutions?

[EdwardT]

Hi Raj072283,

Thanks for letting us know. Like what Patrick mentioned, it's possible that it has something to do with not having a C wire. Could you check the power readings of your Nest Thermostat? You can see this by going to Settings > Technical Info > Power.

Thanks,

Edward

[EdwardT]

Hi Raj072283,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[aatienza]

Hey Raj072283,

Appreciate the help, Edward. Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.

Thanks,

Archie