Immersion heater not working

[Dane2594]

I've pulled it apart and it says 13/20 amp 250v. I can't seem to find anything on screwfix that says it's 20a with a fuse. They are all plain switches only from what I can see. The only fused ones are marked as 13a.

Your Immersion uses a double pole switch for a reason, when it is switched off it cuts the Live and the neutral supplies, do no mess around with it get someone that knows what they are doing

Swapping this should be plug and play once I find the right part, my problem was fault finding as I've not encountered problems before. The input wires go into the feed, and the output to the element go into the load in the correct L/N terminals which I'm happy to do. Everyone else have all been happy to offer helpful advice and don't seem to be bothered about me having a poke around.

 

[ianmcd]

But you have posted twice that N-E you have 240v , this is completely wrong and if you do indeed have that , then you should leave it to a professional

 

[JohnD]

I can't seem to find anything on screwfix that says it's 20a with a fuse.

Immersion heater switches don't have fuses.

They don't need them because the heater is on a dedicated radial circuit from the consumer unit ("fusebox") that is at 16A.

Show us a photo of your old switch, front and back, and the wires that go into it. And of the CU, close enough to read the labels and markings.

The switch should be 20A DP, preferably with a neon or LED indicator.

Turn off the power at your CU before you start.

You seem to be assuming that the switch is faulty. This may not be the case.

Most likely you have a bad connection on an N terminal somewhere, but you might have a damaged cable.

 

[Dane2594]

Immersion heater switches don't have fuses.

They don't need them because the heater is on a dedicated radial circuit from the consumer unit ("fusebox") that is at 16A.

Show us a photo of your old switch, front and back, and the wires that go into it. And of the CU, close enough to read the labels and markings.

The switch should be 20A DP, preferably with a neon or LED indicator.

Turn off the power at your CU before you start.

You seem to be assuming that the switch is faulty. This may not be the case.

Most likely you have a bad connection on an N terminal somewhere, but you might have a damaged cable.

That makes a lot more sense I've just been to an electrical store with my old switch and got a new one. The old switch was fused for some reason who ever wired it up put one in. It does look ancient.
I now have -
240v L-N and 0 N-E and a hot pipe.

Thanks to everyone who provided useful information, it was a broken wall switch. One side of the switch had snapped so it wasn't making a connection on one of the terminals.

 

[Dane2594]

looks like a high resistance fault in the supply. Perhaps the wall switch is burned out or someone put a nail through the cable.

It could also be a wiring error, but you say it used to work.

Thank you, was a broken switch!

If you have Neutral (N) to Earth (E) at 240v and 0V from Live (L) to Neutral then you have a fault. I'd be back looking at a possible issue with the wiring, specifically the Neutral if it's showing 240v to/from Earth. Check your supply voltage to the fused spur and check you have -

L > N = 240v
L > E = 240v
N > E= 0v

If you do then check the wiring to the element for continuity. If you have the same results as you found, 240v from N > E then I'd be checking for continuity back to the consumer unit.

Checked the fused spur and the input was the correct figures, but the output (spur to the element) was showing figures stated in my original post. Thanks.

I really don't see what the problem testing it is!

It just needs to have 240v across the live and neutral at the inlet connections to the heater.

Then 240v across the element itself.

If so then it must work! If the parts are OK !

I don't see why any plumbers were unable to identify the problem. Unless of course they thought that you did not intend to pay them for the diagnosis.

My experience is that people who have started to change parts themselves seem to think that a professional should come and give a free diagnosis. One of their "tricks" is to ask for a free estimate to do the repair !

I always would charge for any visit !

As mentioned before one plumber had a neon screwdriver which made me lose faith straight away, while the second for some reason thought my original figures was correct, therefore he didn't know what else to do so he left. Thank-you for all your help it's much appreciated!

 

[Agile]

It was really such a simple fault!

 

[DP]

Thank you, was a broken switch!

As mentioned before one plumber had a neon screwdriver which made me lose faith straight away, while the second for some reason thought my original figures was correct, therefore he didn't know what else to do so he left. Thank-you for all your help it's much appreciated!

Why?
Neon lights on L and light on N terminal.
I would not even reach for the multimeter as I would be tracing back to the point where the neon does not light on N and will have found the fault!!