After installing nest thermostat, exhaust fan cycles continuously every couple seconds.

[Kabes]

I have installed a google nest thermostat and since i did, the furnace inverter/exhaust fan cycles on and off  every couple seconds even when a heating or cooling event is not asked for.  It is a four wire forced air natural gas system W-R-G-Y.  A power connector was also installed incase it was a "C" wire issue and it still did not fix it.

Google troubleshooted it on the phone and thought it may have been faulty so it was replaced and the new one does the same thing. 

When hooking up the old programable thermostat, the system works normal. Any suggestions how to fix this?  

[Patrick_Caezza]

Post a picture of the original thermostat's wiring.

[Kabes]

[Kabes]

I also tried using the G wire as a C wire and also tried a power connector for a C wire

[Patrick_Caezza]

Check and make sure that you don't have a heat pump system.

You can look at the terminal block on the control board in the furnace/air handler and see what the white wire is connected to.

[Kabes]

Thanks for your help.  I do not have a heat pump.  There is no reason other than something weird going on with the nest that may not be compatible with my system.  It should work but it doesn't so I got tired of the frustration of trying to make it work and I have returned the nest and purchased a honeywell smart thermostat and everything worked fine in minutes.

[MelbaDT]

Hey folks, 

Thanks for helping here, Patrick_Caezza. 

Kabes, sorry to hear what you've been through but thanks for trying to troubleshoot with us. I completely understand how you feel and we're definitely sad to see you go. 

Should you want to give our thermostat a shot again in the future, you know where to find us. 

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.
 

Best, 

Melba