An immersion heater is, simply put, a number of elements, usually 3, elements, a screwplug and a IP rated terminal box to protect the connections.


3 of these (preferablynot chopped up) and

screwplug sizes

…one of these, drilled through, for the elements to be braised or welded into…

Terminal box

…and one of these to attatch to the screwplug, to house the terminals and wiring.

And, in the best Blue Peter traditions, here’s
one we made earlier…

 Immersion Heater

PII Industrial Immersion Heater

The heater is then screwed throught the side of the tank using a weld boss…

weld boss

Mild steel weld boss

Mild steel tanks require mild steel weld bosses, and likewise, stainless steel tanks require horribly priced stainless steel weld bosses. I’ll tell you what brass bosses are used for when I find out.