Tesy digital heater shows E11; unit may not respond to Wi‑Fi or smart control functions.

Safety first: Turn off power before removing covers. Communication faults are low-voltage but covers may expose mains wiring.

Steps:

• Locate Wi‑Fi module: On Tesy smart models, the Wi‑Fi module is usually a small daughterboard or plug-in module near the display or main board.
• Check connection: Ensure the Wi‑Fi module is firmly seated in its socket and that any ribbon or plug connectors are fully inserted.
• Inspect for damage: Look for signs of moisture, corrosion, or physical damage on the Wi‑Fi board.
• Reset network settings: Use the front panel controls to reset Wi‑Fi settings (see user manual). Then attempt to reconnect to your router.
• Replace Wi‑Fi module: If E11 persists and the module appears faulty, replace it with a compatible Tesy Wi‑Fi / smart module.
• Firmware compatibility: In rare cases, the main board firmware must be updated to work with a new Wi‑Fi module; this should be done by an authorized service center.