Thermostat displays E11 and cannot join the Meross cloud; local control may still work.

Safety: No electrical hazard for this fault; no need to power off for network troubleshooting.

Steps:

• Check internet access: Confirm your router has internet access and that other devices can reach external sites.
• 2.4 GHz only: Ensure the thermostat is connected to a 2.4 GHz network (Meross devices typically do not support 5 GHz). Disable AP isolation and ensure the SSID is broadcast.
• Router settings: Temporarily disable firewall rules or parental controls that may block outbound connections. Ensure DNS is working (try using a public DNS like 8.8.8.8).
• Re-add device: In the Meross app, remove the thermostat and perform a fresh pairing. During setup, allow the app to update firmware if prompted.

Outcome: If E11 persists on multiple networks, the communication stack on the thermostat may be corrupted; contact Meross support or replace the unit.