Fan stays on always whenever nest display is on base - only way to stop fan is to remove display

[prstauffer]

Problem

Fan always stays on whenever nest display is on base - only way to stop the fan is to remove display.  None of the fan controls in Nest/Settings, Nest/Fan, or Nest App can turn off the fan.   During a "Test" of the fan control function, the display says  "Fan on" (when it is on) but also says "Fan off" when the fan remains on (always).  No control on display or Nest App will turn the fan off.  Only way to turn off the blower fan is to remove the display face or switch off the furnace circuit breaker.

Additional info

The fan does shift to different speeds momentarialy as if about to shut off, but then kicks on again -it never really turns off just shuffles speed occassionaly.

I have two household furnace/AC units (one furnace has two zones - upstairs and downstairs - and thus had two programable thermostats previously) and the other furnace operates off one separate thermostat..  Thus I bought 3 Nest Learning thermostats.   One Nest was easily setup and is working perfectly on the separate furnace/AC.  The other furnace worked fine previously with two identical thermostats (and identical to the third separate unit) using four wires (RED, WHITE, GREEN, and YELLOW). There was a jumper in the base from Rh To Rc for RED wire - dont know what that did. Is it possible I am getting feedback between teh two Nest controllers?  BUt I dont think so becasue I tried disconnecting all wires from one thermostat location and controlling hte furnace from only one Nest.  Again teh blower fan goes on immedately and never turns off as soon as the display is installed over the base.  Nothing can turn off fan, except removing the display from the base.

The Nest instructions say not to use a jumper - but there are identical Rh and Rc posts in the Nest base - SO MAYBE I JUST NEED TO INSTALL A JUMPER BETWEEN RC AND RH to make the blower fan turn off when not heating????

I have a Payne Model PG95SAS Gas furnace/AC unit

[bbnbdy]

Mine just started doing the same thing about a week ago. my power went out. When the power came back on, the fan was blowing constantly, whether or not a/c or heating was on. I could not shut off the fan except for turning off the power. I ended up replacing the display with another that I just happened to have and now it works correctly. When I installed the new one, I had to reset it to factory settings since I had used it at a different location. I didn't think to reset my existing one to factory settings. You might try that. 

[Jake]

Hey all,

Apologies for the delayed response. I wanted to follow up and see if you ar still having any issues with the fan always being on. Please let me know, as I would be happy to take a closer look into the issue and assist you further. 

Best regards,
Jake

[bbnbdy]

Hello. No. I could find no fix. I happened to have an extra Nest that I used in my office. I swapped them and my new nest works fine. I would like to find some fix for the one that suddenly stopped working. I still have it, and my new one has a scratch on the display.

[prstauffer]

Hi Jake

No I still have same problem.  I spent hours trying everything to get two Nest learning thermostats working together on my two space heating/cooling system.  I had two programable (analog) thermostats working fine before, but nothing I do will allow both Nest to replaec the two previous thermostats.  Fan always running when both Nest installed.  I talked with Nest service person for over two hours and she gave up confused, asked me to send it back for a replacement.  The replacement did the same thing.  Fan always on regardless if I connect four wires (like the previous thermostats) or connect the 5th common wire.  Very frustrating.  After spending over 6-8 hours over three days trying every combination, I have taken a break leaving it with one nest and one analog thermostat.  Now the nest thermostat is confused and will work properly manually but will not connect to the network which it sees but will not connect.  I have a third nest thermostat that works perfectly on the other heating system in the house, separate from the two space heater.  Obviously I just wasted 3 x 275 on Nest system that just takes time and frustration with little benefit. 
Frustrated....... 

[Cinemanovel]

Hi! I’m having the same issue. On my second nest. Power went out and now fan is always on

[Chappy911]

I am currently having this problem when installing my new nest thermostat. The thermostat tells me it does not detect a wire in G and I clearly have placed and replaced this wire 8 times. The fan runs continuos even without the G wire hooked up.

[EdwardT]

Hi Chappy911,

Thanks for reaching out. I'm sorry to hear that you're having an issue with your Nest Thermostat. I'd love to know more about this. Could you check if the fan would still run even if the display of your Nest Thermostat is not attached?

Thanks,

Edward

[Chappy911]

Yes it does

[Jake]

Hey there,

I wanted to follow up and see if I could be of any help. Your heating system control is perhaps holding the system on. If the heating system continues running after the thermostat has been removed from the backplate, the problem could be in the control system of your furnace/heating system. I would recommend having a HVAC pro come out and take a closer look. Please let me know if you have any questions from here, as I would be happy to take a closer look and assist you further. 

Best regards,
Jake

[EdwardT]

Hi Chappy911,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[Chappy911]

Called the HVAC guy like Google wanted me to.  He said he could not figure out why neither of the nest products I purchased would not work.  HVAC guy said send the 2nd nest back also (like I did the first nest) and try an Ecobee.  

[EdwardT]

Hi Chappy911,

Thanks for the response. We'd like to know more about this. Please fill out this form so we could investigate further.

Thanks,

Edward

[EdwardT]

Hi Chappy911,

I'm checking back in. Were you able to fill out the form? Let us know if you have questions and we'd be happy to assist you.

Thanks,

Edward

[EdwardT]

Hi Chappy911,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Thanks,

Edward

[Jhonleanmel]

Hi everyone,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this thread after 24 hours.

Thanks,
Mel