On the covered Google Nest thermostat, W5 means the thermostat cannot connect to Wi-Fi. Google says this can indicate a hardware malfunction, and the thermostat may need replacing. First, confirm it is a real W5: open the Quick View menu, go to Settings, turn the ring to Network and look for "Error - nest.com/w5".
Differential
Likely causes of “Google Nest thermostat code W5”, and how to tell them apart
- 1
A thermostat Wi-Fi radio that has failed
What separates it W5 persists after a restart
How to confirm Google says it is likely a hardware malfunction
- 2
A temporary glitch
What separates it W5 appears once
How to confirm Restart from Settings, Reset, Restart
- 3
A router that refuses the thermostat
What separates it Other devices connect
How to confirm Check the router's filters
- 4
A weak signal at the thermostat
What separates it The signal drops in that room
How to confirm Move the router or add an access point
- 5
A password change
What separates it The thermostat has old details
How to confirm Reconnect under Settings, Network
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether the Network menu shows the W5 message
- Whether a restart changed it
- Whether other devices join the same Wi-Fi
- How old the thermostat is
Try in this order
0 of 8 completedWhat to do first
ReversibleConfirm it is a real W5: open the Quick View menu, go to Settings, turn the ring to Network and look for "Error - nest.com/w5".
Correct only the documented fault domain
ReversibleGoogle's steps: if the Network menu shows the W5 error, restart the thermostat from Settings, Reset, Restart (this does not lose your settings), then try to reconnect under Settings, Network. If W5 persists after a restart, Google says it is likely a hardware malfunction and the thermostat needs replacing; contact Google Nest support with the help code and the serial number from the back of the display. The code does not appear in the app, only on the thermostat.
Confirm it is W5
ReversibleQuick View, Settings, Network.
Restart the thermostat
ReversibleSettings, Reset, Restart.
Reconnect under Network
ReversibleChoose the network again.
Test another device
ReversibleOn the same Wi-Fi.
Watch whether W5 returns
ReversibleAfter the restart.
Contact Google Nest support
ReversibleIf it persists.
Model-specific
What is true of this model and not of its siblings
- Confirming the code
- Open the Quick View menu, go to Settings and turn the ring to Network. A real W5 shows an error with the address nest.com/w5. A thermostat that merely shows a weak signal is a different problem.
- What Google says
- If the Network menu shows W5, restart the thermostat from Settings, Reset, Restart, which does not lose your settings, and try to reconnect. If W5 persists, Google says it is likely a hardware malfunction and the thermostat needs replacing.
- Before you replace it
- Check whether the thermostat is under warranty and whether the problem began after a power event. Contact Google Nest support with the serial number, which is under Settings, Technical Info.
Stop boundary
When this stops being a self-service repair
- !If W5 persists after a restart, Google says the thermostat probably needs replacing
- !Contact Google Nest support
- !Check warranty before buying a new one
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What does W5 mean on a Google Nest thermostat?+
The thermostat cannot connect to Wi-Fi. Google says this can indicate a hardware malfunction, and the thermostat may need replacing.
Will a restart lose my settings?+
No.
Is it my router?+
If other devices connect, probably not.
When do I replace it?+
If W5 persists after a restart.