Nest thermostat shows E10 and cannot connect to Wi-Fi.

Note: E10 affects remote control and app connectivity but does not usually stop local HVAC control.

• Check Wi-Fi signal: Stand near the Nest with a smartphone and check Wi-Fi strength. If weak, move the router closer, add a mesh node, or use a Wi-Fi extender.
• Verify network settings: Ensure your router is broadcasting 2.4 GHz (for older Nest models) and using WPA2 or WPA3 security. Avoid hidden SSIDs and captive portals.
• Re-enter Wi-Fi credentials: On the Nest, go to Settings > Network, forget the current network, and reconnect by carefully entering the correct password.
• Reboot router and Nest: Power cycle your router and modem, then remove and reattach the Nest display to reboot it.

If E10 persists and other devices connect fine, the Nest Wi-Fi radio may be defective and the display module may need replacement.