Blower Fan turns off while Air Conditioning compressor is still running

[JohnG2405]

I have the Nest Model E Thermostat and my blower fan shuts off 2 minutes after cooling starts.  It then will intermittently come back on and shut off while the compressor continues to run the entire time.  The only way I can make the blower fan cycle on is to physically remove the Thermostat from the wall and then place it back on.  Even when I do that the majority of the time the fan shuts back off after 2 minutes, only on occasion does it stay on.  I found these 2 past posts where many other users seem to have issues, but I don't see why I should have to rewire my whole house when Google claims that the thermostat only requires 4 wires.  Is it time to completely abandon Nest Thermostats and find a better/more reliable product?

https://www.googlenestcommunity.com/t5/Nest-Thermostats/blower-fan-turns-off-after-2-minutes-when-Ne...

https://www.googlenestcommunity.com/t5/Nest-Thermostats/blower-fan-turns-off-when-Nest-is-engaged-in...

Please help!

[luciaaa]

Hi, @JohnG2405,

Thank you so much for posting in the community. I apologize for the inconvenience caused by your blower fan turning off after 2 minutes. I’m here to help and find a solution. 

To identify the best step and fix this, please answer the following questions:

• 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?
• Are you receiving any power error codes?
• Have you experienced any power outages within the last few days or weeks?
• Is this a new installation? 
• Has there been any recent changes or upgrades to your HVAC system?
• Does the issue happen on heating only, cooling only, or both?
• Do you have a common ground wire or C wire?

In the meantime, please try the following 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.
• I suggest performing a restart. You can refer to the following article: Restart or reset a Nest thermostat.

Please let me know how it goes.

Best regards,

Ana

[JohnG2405]

Hi Ana,

These seem like a lot of the suggestions that were given to the 2 previous posts I referenced above and were not of much help but I have answered them below.  Please let me know how to fix the issue since many users seem to be having it.  If the answer is just that the older models were not designed to work more than a few years please let the community know that so we are not burning out our compressors due to a poor design.  Thanks

• Would you mind sharing a photo of your wiring configuration?  I am not currently at the house so do not have a photo.  The wiring configuration is that wires are connected to R, Y, G and W which is all the website said was needed when I installed it.
• Do you have a conventional or a heat pump system?  Conventional
• When did your system last receive a professional maintenance check?  Last month
• Are you receiving any power error codes?  No
• Have you experienced any power outages within the last few days or weeks?  No
• Is this a new installation?  No
• Has there been any recent changes or upgrades to your HVAC system?  Yes I had a new compressor and coil installed but this was a problem before the installation.  I was hoping the new compressor might fix the issue.
• Does the issue happen on heating only, cooling only, or both?  Both
• Do you have a common ground wire or C wire?  No

All of the trouble shooting tips did not work FYI.

Please provide a timely answer.

[ovidioj]

Hello @JohnG2405,

Thank you for sharing the details about the issue. I apologize that the previous suggestions were not helpful. Based on the information provided, it seems there may be a compatibility or configuration issue between your Nest thermostat and HVAC system.

Since you've confirmed no error codes are displayed on the thermostat, the issue likely lies with the HVAC system itself. It's recommended to consult with a professional HVAC technician to diagnose and resolve the problem. You can find a certified Nest Pro HVAC technician here: Nest Pro HVAC technician.

Please let me know if you have any other questions. Thank you.

Regards, 
Jorge

[JohnG2405]

Hi Jorge,

The HVAC system was fully inspected when the new compressor was installed and no issues were found.  Furthermore when I attach the 6 year old Honeywell thermostat back to the wall the system works fine.  Judging from all the past posts I referenced in addition to my own it seems that google does not have an answer to why it's Nest Thermostat E fails to turn on the blower fan for more than 2 minutes or works intermittently. 

My thermostat worked fine for the first 4-5 years, why would is suddenly start having the issues all of the other users I referenced were having?

Is it possible that a C wire is needed even though Google said it was not and was compatible without one? (a user in a previous post said they had installed one and it then started working)

Please advise.

Thanks

[luciaaa]

Hi, @JohnG2405,

Thank you so much for your response and all the information provided. It seems that after you installed your previous thermostat, the blower worked.

To provide you with all the available resources to resolve this issue, let's test the terminals on your Nest thermostat following these steps:

• Turn off the HVAC system's power at the breaker switch.
• Remove all the wires and wait one minute.
• Reinsert the wires
• Turn on the breakers, select cool mode, and check if the fan turns on.

If the blower continues to turn off after 2 minutes, please fill out this form with all the necessary information. Once you've completed the form, let me know. A member of our higher team will contact you shortly to assist.

Keep me posted,

Best regards,

Ana.