Im just getting error E74. My nest is a 3rd generation 2 years old

[Sfarelo]

It was working and now is not

[AdilAnsari2415]

1. Factory reset each Nest thermostat
   → This removes the old technician’s email completely (you don’t need that email).
2. Set it up again using your own Google account
   → Open Google Home → Add → Set up device → Nest Thermostat.
3. If the thermostat is very old and won’t connect, it may be an early model no longer supported → you may need a replacement.

[Derickf]

Hi @Sfarelo,

Thank you for posting in the community. I’m sorry to hear that you are having trouble with your Nest Learning Thermostat 3rd gen because it stopped working and now it is showing an E74 error code. I understand how difficult it must be when your device doesn’t work as expected. I'm happy to assist.

@AdilAnsari2415, Thanks for jumping in.

To gather the necessary information, please answer the following questions:

• When was the last time the air filter was changed or the HVAC unit had maintenance?
• Have you checked if the breakers are on?
• Have you had any power outages in your area recently?

I'll be waiting for your reply.

Best regards.

Derick.