Immersion heater switch in kitchen not lighting up

[bodge it and leg it]

We have an immersion heater switch in the kitchen that has neon light on it. Got up this morning and no hot water and realised the neon light on the switch was not illuminated even though the switch was on.

I have checked the fuse box and nothing seems to have tripped.

I have removed the socket itself and tested the live and neutral wires with a mains tester screwdriver and the screwdriver lights up so there seems to be a feed both coming in and out.

Any ideas or help appreciated.

 

[breezer]

throw your screwdiver away, they are useless.

either its the imersion heater itself, its stat, or you have no neutral (unlikely but those screwdrivers cant tell you that)

 

[Spark123]

My initial thought is a problem with the neutral, could be a broken switch, loose connection in switch or CU. Can you get a multimeter and check the voltage at the switch? Measure on an AC volts range exceeding 250v very carefully.
With the switch on, check the voltage across phase and neutral, then phase to earth and neutral to earth, do both the supply side and the load. What do you get?

 

[kai]

Have you also checked the 13amp fuse which is often mounted under a small hatch adjacent the double pole switch? - it is identical to a standard plug fuse - it could be a blown fuse there.

 

[RF Lighting]

Have you also checked the 13amp fuse which is often mounted under a small hatch adjacent the double pole switch? - it is identical to a standard plug fuse - it could be a blown fuse there.

It is unusual to have an FCU fitted on an imm heater circuit. It is usualy just one or two 20A DP switches.

 

[kevnurse]

Why would your water heater switch be ON and heating the water before you get up in the morning? Are you using off-peak electricity for hot water and heating? If so, did your storage heaters warm up overnight? There's more to this than meets the eye.

 

[bodge it and leg it]

Okay heres the explanation that has caused all my problems. Thanks for all the speedy possibilities though.

I have been fitting a new kitchen fitted and some idiot(myself) has drilled an hole for a baton support straight through the cable and taking out the neutral in the process, good job I missed the live. For a tempory measure to get the immersion heater backup and running I have cut the damaged cable and inserted a 20 amp junction box and fed the new cable into the back of the switch.

I know I should called a sparky straight away but no cash spare to pay their call out rates on New Years Day.

This leads me to my next question what is the going rate for a new cable to be put in. Am I right in thinking that it is just one feed coming from the fuse box.

Oh and just to say the Immersion is on a timer so one has hot water when one awakes, as to speak.
__________________________
Lynda, moderator

costs / rates / prices, please see forum rule 9

 

[kevnurse]

For a temporary measure to get the immersion heater backup and running I have cut the damaged cable and inserted a 20 amp junction box and fed the new cable into the back of the switch.

OK, have you checked your new terminations all secure? Give them all a tug. You've hit the cable once, that you know of. Is it possible that you have hit it somewhere else?

Tell us more about this timer. Does it control only the water heater? Where is it in your circuit? In your first post you mentioned the light in the switch. Were you referring to the neon light on the timer? Or do you have a separate switch and a timer.

You might think my questions about the system are irrelevant, but we need to know the complete system before we can diagnose the problem.

There is still one thing that intrigues me about your hot water timing. Do you have an off-peak electricity supply or is your water heater on the normal domestic supply?

 

[bodge it and leg it]

Ok the answers to your questions.

I cut the cable and inserted the junction box at the point where i had drilled through the cable. All connections seem fine now.

The switch in the kitchen has a neon light on it and by the look of it the feed goes into this switch and then travels directly up into the bathroom cupboard. (This is where the immersion heater/tank is) In the cupboard is a timer where the feed from the kitchen switch goes into. This controls when the water comes on and goes off.

All this is on the domestic supply.

One question I have though is, Under all the new regulations do I have to have this feed that was damaged rewired or can I leave the junction box attatched to the wall.

Thanks

 

[kevnurse]

Firstly, your junction box (JB) repair is a practical solution and is OK, provided that it remains accessible (screws loosen off over time).

Are you sure that you have properly wired the JB and that the cables are not damaged elsewhere?

Check that you have properly re-wired the back of the switch and that you haven't accidentally put the supply wires into the load terminals and vice versa.

Unless, by sheer bad luck you suffered another fault co-incidentally, it must be something you've done.

As a footnote, why are you using the domestic tariff to heat your daily hot water supply? Its the most expensive way to do it.