A boiler for heating a flow capable medium, especially for heating water,
comprising a boiler housing made from plastic and a heater protruding
through a mounting hole in the boiler housing into the interior of the
boiler housing, being fixated in the mounting hole through a fixation
means. Furthermore the interior diameter of the mounting hole in the
boiler housing is at least in sections approximately identical to the
outer diameter of the heater and the heater has an unheated section in
the area of the mounting hole.