The following steps have to be performed by a qualified person as you may be exposed to electrical hazards and/or damage the product. Make sure the power supply is disconnected if required and the water supply is disconnected if required.
Drain your water heater until LSL in the Info screen (Info) of the Touchscreen switches to the lower position (Lo).
NOTICE: Few seconds after the switch, an adjustment is performed by the water heater. Fill manually if Alarm 225 appears.