Display shows E11; unit may heat briefly then shut off

Safety first: Turn OFF power and allow the unit to cool. Hot water can cause severe burns; use caution.

Steps:

• 1. Check temperature setting: Reduce the set temperature on the control panel to a safe level (e.g., 49–55°C / 120–131°F).
• 2. Descale heat exchanger: If you have hard water, perform a descaling procedure using service valves and a pump to restore proper heat transfer.
• 3. Inspect outlet NTC sensor: Ensure it is properly attached and not exposed to ambient air. Test its resistance and replace if readings are out of spec.
• 4. Check mixing valve (if equipped): For models with an integrated thermostatic mixing valve, verify that hot and cold lines are correctly connected and that the valve is not stuck. Replace if it does not regulate temperature properly.
• 5. Reset and test: Restore power and run hot water, confirming that outlet temperature is stable and E11 does not recur.

Professional help: If the unit continues to overheat, a technician should verify sensor calibration and control board operation.