Thermostat displays E8 and will not connect to Wi‑Fi or Emerson cloud services

Safety first: No high-voltage work is involved, but avoid removing the thermostat from the wall while powered if you are not comfortable with low-voltage wiring.

Steps to troubleshoot:

• 1. Check home Wi‑Fi: Verify your router is powered, broadcasting 2.4 GHz (most Emerson smart thermostats do not support 5 GHz only), and that other devices can connect.
• 2. Verify SSID and password: In the Emerson app, re-enter your Wi‑Fi network name and password carefully. Avoid special characters if possible.
• 3. Move router or add extender: If the thermostat is far from the router or behind multiple walls, improve signal strength by relocating the router or adding a Wi‑Fi extender.
• 4. Reset network settings: On the thermostat, go to Wi‑Fi or network settings and select “Forget Network” or “Reset Wi‑Fi.” Then re-pair the thermostat with the Emerson app following the on-screen instructions.
• 5. Power cycle thermostat: Turn off the HVAC breaker for 2 minutes, then restore power and attempt reconnection.
• 6. Persistent E8: If the thermostat cannot see any networks or repeatedly fails to connect while other devices work, the internal Wi‑Fi module may be defective.

When to call a professional: For confirmed Wi‑Fi hardware failure, contact Emerson support for warranty options or replace the thermostat.