1) disconnect the heater from electrical grid
2) before reconecting the DAFI heater into electrical grid water must flow through the heating element for approx 1 min.
It must be done by turning the hot water knob on. (pic. 1,2)
3) the unit is now ready to be reconnected to electricity, provided the above mentioned action has been performed. (pic. 3)

DAFI WATER HEATER - In-Line model

DAFI WATER HEATER - Flexible model