Immersion seems stuck on, but off at fuse box

[M-R]

Hi all,

I seem to have an issue with my immersion heater in that it’s constantly on.

It’s off at the switch next to the water tank (as usual) and its fuse is off in the fuse box.

Can it be stuck on despite those two things being off?

We did have a power cut recently and all the fuses tripped, so I put them all back on, including the immersion.

Then I remembered that the immersion fuse used to be off so have switched it back to off but the water remains hot all the time.

Could the power cut have affected it?

And any ideas for a fix or is it a job for the professionals?

Many thanks in advance.

Michael.

 

[terryplumb]

Immersion heater must be connected to a live circuit if it is heating water. Is the hot water also heated by a gas boiler ?

 

[JohnD]

Please post some photos of your hot-water cylinder

And all the wires, switches and cables around it

And the pipes going into it.

And of your consumer unit(s) ("fuseboxes") showing the circuit labels

 

[M-R]

Immersion heater must be connected to a live circuit if it is heating water. Is the hot water also heated by a gas boiler ?

That’s what I don’t understand - the switch and the fuse are both in the off position.

Yes, there’s also gas to heat the water but the water has been hot even when the gas-fired water heating has been off.

 

[terryplumb]

Show us some pics as JohnD asked.

 

[CBW]

I’ve seen consumer units labelled up wrong, could yours be, and a faulty switch?

 

[ianmcd]

As others have suggested , Pics are best

 

[M-R]

Please post some photos of your hot-water cylinder

And all the wires, switches and cables around it

And the pipes going into it.

And of your consumer unit(s) ("fuseboxes") showing the circuit labels

Hi John D,

Sure, see attached. Thank you.

 

[terryplumb]

The switch on the wall ,with cable from it to the immersion, has a fuse. The little rectangular bit with a screw holds the fuse. Remove the fuse.
I doubt the immersion is heating the water ,have you been running the central heating ?

 

[JohnD]

I don't believe the electric immersion element is doing it. Anyway, the cap of yours is scorched which is a bad sign so there may be a fault.

Is the tapwater scalding hot?

Look at the rectangular silver box with three pipes going into it in a T shape.

Which of the pipes is hot?

Can you feel or hear the green pump running?

Observe the cream thermostat on the side of the cylinder. Turn it down to the lowest possible sagging. Does it click?

Does the silver box whir and the pump stop?

If not, turn the stat down further, then all, the way up. Any click?

(When you have finished, reset it to 60)

When was the silver box replaced, and that horrible cable patch covered in yellow tape done?

 

[JohnD]

P.s.

You should invest in some foam pipe lagging. Your hot pipes are probably 22mm but you might have some old 28mm

 

[JohnD]

BTW some shoddy electrical work has been done, so you can't rely on the labels on the consumer unit being correct.

 

[M-R]

The switch on the wall ,with cable from it to the immersion, has a fuse. The little rectangular bit with a screw holds the fuse. Remove the fuse.
I doubt the immersion is heating the water ,have you been running the central heating ?

Thank you.

I’ll try that.

We haven’t been running the central heating - but when we do it does passively heat the water in the tap a bit but I don’t think it’s that.

 

[M-R]

BTW some shoddy electrical work has been done, so you can't rely on the labels on the consumer unit being correct.

Yep, it was a bit of a bodge job by the last owner who bought it, did it up (a bit) to move it on.

I’ll test the switches on the consumer unit to see if they match reality.

 

[Tigercubrider]

Flip off all switches (if the immersion is actually on)
And switch back on individually to see if the labelling is at fault
As said, you have scorch marks