Nest thermostat won't run the fan alone in Heating mode

[Heecheeboy]

I cannot get the Nest thermostat to run the fan alone in Heating mode. The fan ran by itself very well during the summer in Cool mode when I used the app for the thermostat itself. The G wire is there, and as noted it performed well during the summer. Has anyone run into this before?

[gmelanymelissa]

Hi Heecheeboy,

Thank you for posting in the community. I understand you're unable to get your Nest Thermostat to run the fan alone when it's set to Heating mode, even though the fan ran successfully by itself during the summer and the G wire is connected. I'm here to help!

To better assist you with accurate information, I’d like to ask a few questions:

• What is the model of your Nest Thermostat? Here’s a helpful article about how to identify your thermostat model.
• What type of HVAC system do you have?
• Have there been any recent changes or upgrades to your HVAC system? 
• Would you mind sharing a picture of your current thermostat wiring?

Keep me posted.

Best regards,

Melany