connection problem

elbloke1 — Fri, 24 Oct 2025 14:17:41 GMT

code e299

Re: connection problem

EduardoN — Mon, 27 Oct 2025 23:06:59 GMT

Thanks for contacting this community! I understand that your Nest Thermostat has this error code E299, about this error code I'd like to know more abut this, for that I'll ask you some questions:

What is the specific model of your Nest Thermostat? Here’s a helpful article about how to identify your thermostat model.
Which wires do you have on your system?
Do you have a pre-existing thermostat?
How far away is the thermostat from the router?

This error code means that the C-wire is disconnected and isn’t able to provide power. The thermostat battery will power the thermostat temporarily, but the thermostat will eventually power off for that in the meantime I recommend you the following steps that may help:

Restart the thermostat.
- Nest Learning Thermostat: Go to Settings > Reset > Restart.
- Nest Thermostat: Pull your thermostat off its base > Remove both AAA batteries > Replace the batteries and press your thermostat onto the base until it clicks into place > Your thermostat will take a few moments to turn on and restart.
Reinsert the C-wire:
- Turn off the breakers > Remove > Reinsert the C-wire into the terminal.

Please feel free to share any additional details you think might be relevant.

Best regards,
Eduardo

topic Re: connection problem in Nest Thermostats

connection problem

Re: connection problem