cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 
Help

New thermostat causing fan to cycle

CKing
Community Member

4 weeks ago

My old nest thermostat died, so I bought a new one. I have 4 wires, and I initially plugged the green wire into G. My fan was just cycling on and off like every 10 seconds and the AC never came on. I switched the green wire to C (that’s where it comes out of my furnace and how the previous nest was wired) and the AC would come on, but when it’s not running the fan still kicks on and off.  I have included pictures of the new thermostat wiring as well as the wires in the furnace.  Nest is currently disconnected in hopes of not damaging the fan.

IMG_1357.jpeg

 

IMG_1356.jpeg

 

0 Kudos
1 REPLY 1

GabrielaG
Community Specialist
Community Specialist

3 weeks ago

Hi @CKing,

 

Thanks so much for reaching out to the community. I'm sorry to hear that your Nest Thermostat is causing the fan to short cycle and that the AC isn't turning on. I understand how frustrating that can be, but don't worry; I'm here to help.

To help me troubleshoot this issue more effectively, could you please answer the following questions?

  • Do you see any error codes on the thermostat screen?
  • When was the last maintenance service and cleaning?
  • Have you set up a temperature schedule for your thermostat?
  • Does this issue occur with heating, cooling, or both?

In the meantime, you may find this article helpful: Fan control with a Nest thermostat.

I look forward to your response so we can find a solution for you soon.

 

Best regards,

Gabriela

0 Kudos