over heating shower

[Tim+]

How to use a multimeter. ;-)

Tim

[arwadsworth2020]

I would be helped to say that the element is working:-)

[Terry Casey]

We had this problem a couple of times in our old house. In both cases it was caused by the immerion casing corroding and exposing the element. (40 year old electrics, so no RCD to trip!)

We had one of those stacked units with cold tank at the top and hot water cylinder below. Draining the tank was the first problem as the drain c*ck was only a couple of inches above the floor so I had to fit a long hose, run it across the bathroom and hang it out of the window so that the end was below floor level, then turn off the water supply once the flow was established.

As the contraption was in the corner just beyong the end of the bath, access to the immersion itself was not easy either and, as you say, it was a pig to remove, even the second time (I greased the thread of the first replacement).

I fitted a corrosion resistant type the second time around.

As the new element comes complete with a new stat, it killed two birds with one stone.

[John Rumm]

Well we kind of inferred that from the water getting too hot and all ;-)

However if the stat failure is also accompanied by corrosion of the pocket that it sits in, such that it leaks and could damage the new stat, or even prevents withdrawal of the stat, then replacing the whole immersion might be required.