Disable Fan with Learning Nest 3

[uspokelly]

I recently installed a Learning Nest 3 thermostat for my HVAC system. Everything is working fine, wiring is correct but fan will randomly turn on and I am unable to turn it off. The only way to turn off is to cut power (breaker). I am able to turn the fan on/off manually from my app without issue. The off issue only occurs when the fan turns on automatically. I am in heating mode only currently. Can I prevent/disable the fan from running automatically? 

[EdwardT]

Hi uspokelly,

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 and I have a few questions:

• What type of Nest Thermostat do you have?
• How is your Nest Thermostat wired?
• What is the power reading of your Nest Thermostat? You can find this information by going to Settings > Technical Info > Power.

Looking forward to your response.

Thanks,

Edward

[uspokelly]

Hi Edward, thanks for responding, 

Model: Display-3.7
Backplate model: Backplate-5.26
Serial no. 09AA01AF28220PZT
Updated: Never
Device ID: CCA7C1000038DC53
Software 6.2-27
Battery: 3.86 volts

wired as follows: Left: Y1; G; Rc Right: W1; Rh

hope this helps, let me know if more info is needed.

[EdwardT]

Hi uspokelly,

Thanks for the response and additional information. To isolate the issue, could you check if the fan would turn off if you remove the display of your Nest Thermostat?

Thanks,

Edward

[uspokelly]

Just so I am clear, should I turn on the fan then remove the thermostat to see if it turns off?

[EdwardT]

Hi uspokelly,

Thanks for the response. You're correct. Please try removing the display when the fan is running unexpectedly and check if it will turn off to isolate the issue.

Thanks,

Edward

[uspokelly]

Ok so this evening the fan suddenly went on. I removed the thermostat but the fan continued to run. It will only turn off when I cut the power from the breaker.

[EdwardT]

Hi uspokelly,

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

Thanks,

Edward

[uspokelly]

Form completed.

[EdwardT]

Hi uspokelly,

We got your form — thanks for filling it out. Our team will reach out to you via email to further assist you. Also, please be advised that this thread will be locked after 24 hours.

Thanks,

Edward