Google states that W5 means the thermostat cannot connect to Wi-Fi and may require replacement if a restart does not clear it.
What W5 means
Google states that W5 means the thermostat cannot connect to Wi-Fi and may require replacement if a restart does not clear it.
What you may notice
- The thermostat shows nest.com/w5
- No Wi-Fi networks appear
- The app shows the thermostat offline
- Temperature control may still work locally
Most likely causes
- 01A thermostat Wi-Fi hardware fault
- 02A temporary software lockup
- 03The thermostat needs a restart
- 04A separate network issue without W5
Safe checks, in order
Start with the simplest non-invasive check. Stop as soon as the error clears; repeated resets can hide a condition without correcting it.
Confirm W5 on the thermostat
Check the Network menu; a simple Not connected message is not the same as W5.
Restart from Settings
Use Reset, then Restart; this preserves customized settings.
Reconnect to Wi-Fi
Select the home network after the restart.
Contact Nest support
A persistent W5 code may require thermostat replacement.
Know where to stop
A normal restart is different from a factory reset. Do not erase configuration unless official support directs it.
When to call a technician or support
Contact Google Nest for replacement options if W5 remains after the documented restart.
When you call, have the exact product or vehicle model, model year where relevant, the complete code or symbol, and when it appeared.
Where this information came from
We use the manufacturer's current published guidance as the starting point, then organize it into a safer, beginner-friendly sequence.
Google Nest Help — W5 code Source last checked August 16, 2026. Manufacturer instructions and model manuals take priority over this independent summary.