No Auto Fan Setting For Nest?

[braberley]

Hi,

Bought a home with a 2nd generation Nest thermostat and was surprised to find there is no Auto/On/Off fan setting, like any other thermostat I have ever seen.  With the Nest, you can turn the fan on manually or set a schedule for the fan to come on but you cannot set it to Auto so that the furnace fan comes on when the furnace burner comes on in the winter or the AC comes on in the summer.

Is it possible that the default behavior for a Nest is like Auto, meaning the fan is supposed to come on automatically when the burner comes on, and you can just leave the fan settings off/disabled?  

[johnCNA]

Yes, the fan will always come on automatically when it calls for heat or cooling.

[braberley]

Thanks for the reply. 

Right now the fan schedule is disabled but the fan is running all the time.  I guess this means there is a wiring problem from when it was installed?

[johnCNA]

It is possible that your G wire might be shorted against another wire in the base plate.  A short between R and G will have the fan run continuously.  But before you pull the Nest off the wall to investigate, try the below. 

I have the Learning 3rd Gen thermostat so the menus on your Nest might be different.  But on mine, tapping the screen shows the Mode settings at the top. One of which is Fan.  That option will only allow setting a maximum 12 hour schedule.  Instead, if I select the 'gear' for Settings at the bottom of the screen and then cycle through the blue menu circles, there is a Fan Schedule option.  In that menu, there is an option for 'Always On' in addition to making a schedule.  See if your Nest has a similar menu structure and what the fan settings are there.

[braberley]

I have a 2nd generation Learning Nest but the menu is the same.  Right now the Fan Scheduled is disabled.  If I look at the schedule it says Always On from 12am to 12am, but like said it's disabled so this should have no effect.  Just to be sure I changed it to 15 minutes From 12am to 1am then disabled it again.   

[Ryan_G]

Hey folks,

Thanks for visiting the Google Nest Community. 

Since this thread hasn't had activity in a while, we're going to close it to keep content fresh.

If you have additional questions, feel free to submit another post and provide as many details as possible so that others can lend a hand. 

Hope this helps!

Kind regards,

Ryan

[Jcsilvera]

I have the opposite issue with same thermostat. My fan will NOT come on automatically but I can turn it on manually for any specified time on either the schedule or a time selection on the application. My HVAC company has been here twice and can't fix it?? AC was working fine before I had this installed.