Thermostat shows E7 and cannot connect to the Danfoss cloud or mobile app; local control may still work.

Safety first: Network troubleshooting is low risk, but do not open the thermostat if you are not trained. Most Wi‑Fi issues are resolved via software settings.

Steps to diagnose and fix:

• 1. Check home internet: Confirm that other devices can access the internet via the same Wi‑Fi network. Restart the router if necessary.
• 2. Verify Wi‑Fi credentials: On the thermostat or in the Danfoss app, re-enter the correct SSID and password. Ensure you are using a supported band (typically 2.4 GHz) and security type.
• 3. Improve signal strength: Move the router closer to the thermostat or add a Wi‑Fi extender. Avoid placing the thermostat behind metal panels or in recessed metal boxes that block RF.
• 4. Check router settings: Ensure MAC filtering, client isolation, or firewall rules are not blocking the thermostat. Allow outbound connections for the Danfoss cloud service as specified in the manual.
• 5. Reboot thermostat: Power-cycle the thermostat by removing it from the backplate or switching off its circuit for 30 seconds. After reboot, reattempt Wi‑Fi setup.
• 6. Factory reset (last resort): If E7 persists, perform a factory reset following Danfoss instructions, then reconfigure Wi‑Fi and cloud account. Note that schedules and settings may be lost.

When to call a professional: If the Wi‑Fi module is suspected faulty and the unit is under warranty, contact Danfoss support or your installer for replacement.