Why does the water in my Truma electric boiler not get hot?

There can be several reasons why the water in your Truma electric boiler does not get hot:
Cause

Remedy

No power.

Reconnect the power.

Operation without water; overtemperature protection switches the heating element off.

Switch the Truma electric boiler off, wait ten minutes, fill it with water and switch the Truma electric boiler on again.