Can I fix Google Nest code E10 myself?

Start with these safe checks: If it's very cold outside, this can be normal for the AC. Check again in warmer weather. If it happens in normal weather, have an HVAC pro service the system.

When should I call a technician for code E10?

If it happens in normal weather, have an HVAC pro service the system. Thermostat wiring is low voltage, but switch the HVAC system off at its breaker or service switch before pulling the thermostat off the wall. If the code points to the furnace or outdoor unit, leave gas, combustion and refrigerant parts to a licensed HVAC technician.

Google Nest Thermostat Error Code E10 / E30 / E80: No power to Y1…

What E10 means

No power on the Y1 (cooling) wire. Google says the air conditioner may have tripped a safety cut-out that prevents it from running in very cold weather, or the system needs maintenance.

Also shown as: E30, E80, E160, E196, E296, M13, depending on the model.

Likely causes

AC cold-weather safety cut-out
System needs maintenance

Safe first checks

If it's very cold outside, this can be normal for the AC. Check again in warmer weather.

When to stop

If it happens in normal weather, have an HVAC pro service the system.

Checked against: Google Nest Help: Troubleshoot Nest thermostat help codes. Codes can differ by model and year, so confirm with your owner's manual.