Fan fluctuating when cooling, does not maintain one speed.

[jparker01]

Installed a Google Nest thermostat in the winter after the one that I had failed. Install and setup where very easy. During the winter months it worked perfectly. Once it started warming up and needing cooling in the house I noticed that my fan will not stay at a single speed, fan fluctuates during the cooling process. When it gets close to shutting off the fan slows down so much it sounds like it is going to shut off than ramps right back up to full speed or a half speed. Did I miss something during setup. Forced air furnace, 2 stage heat with air conditioning. When I run the self tests for the heat/cool settings, there is no errors reported.

[luciaaa]

Hi @jparker01,

Thanks for posting here in the community! I'm sorry to hear that the fan doesn't stay at a single stage. I'm happy to help you find a solution for your thermostat.

To better assist you, I'd like to ask a few questions:

• What type of thermostat do you have?
• Would you mind sharing a photo of your wiring configuration?
• Do you have a conventional or a heat pump system?
• When did your system last receive a professional maintenance check?

In the meantime, I suggest following these troubleshooting steps:

• Make sure the fan schedule is disabled on your thermostat. You can refer to the following article: Fan control with a Nest thermostat.
• Ensure all the wires are correctly inserted and lay flat against the terminals.
• Depending on your thermostat model, I suggest performing a restart. You can refer to the following article: Restart or reset a Nest thermostat.

Please keep me posted.

Best regards, 

Ana.