Display shows E11 and the descaling program cannot be started or is interrupted.

Safety first: Unplug the machine before filling with descaling solution.

This error is related to the automatic descaling cycle.

• Follow manual exactly: Ensure you are starting the descaling program as described in the Severin user manual (button sequence, water/descaler ratio, etc.).
• Use correct descaler: Use a Severin-recommended liquid descaler. Avoid vinegar, which can foam and confuse sensors.
• Clean tank and inlet: Rinse the water tank thoroughly and ensure the outlet valve is not blocked.
• Power cycle: Unplug for 5 minutes, then retry the descaling program from the beginning.
• If E11 persists: The flow meter or scale sensor input on the PCB may be faulty and require service.