how immersion heaters work.

[Doc Hudson]

There is only one water cylinder (tank) but two elements in the same cylinder usually.

Doc H.

 

[ProDave]

It's not two tanks, it's one tank.

the bottom heater will heat the whole tank, whereas the top one will only heat the top half.

If you are only using the top heater, you will find it a bit wanting, particularly if you like a nice hot deep bath.

If the plumber can't get the element out, it's time to bite the bullet and replace the tank.  But do stick woth one that has two heaters in from the side like you have already, a lot less troublesome that top mounted elements.

 

[steptoe]

heat rises,

so the element will only heat up the water above it,

it will heat up the water below it, but only very slightly, due to convection the hot water will always be above the element.

 

[Technician]

Is this one of those tanks with a ball cock in the top one and two

tapped holes for heaters in the larger lower one?

Or are there two entirely separate tanks one above the other?

 

[xymalf]

no ball cock - two seperate tanks. cold water is in seperate tank above.

Is this one of those tanks with a ball cock in the top one and two

tapped holes for heaters in the larger lower one?

Or are there two entirely separate tanks one above the other?

two seperate tanks no ball cock. cold water has its own tank above.