Immersion Heater not working - advice please

[bertieshaw]

I would welcome some input regarding a problem with my Immersion Heater. It suddenly stopped working - the neon light in the switch was out, and the fuse has not tripped.
I therefore assumed that the immersion heater element had packed in. Visit today by British Gas engineer (immersion covered by service contract). He checked things out and advised that there was 240v at either side of the immersion heater element and 'therefore there must be a break in the neutral wire - somewhere'. He said because of this it could not be the element itself. He then told me he was not an electrician (gas fitter) and I should call an electrician for help. Before taking further action I would appreciate any comments on whether what he said actually makes sense?? Interestingly, (and I don't know what he fiddled with) I note that the neon light in the switch IS now glowing (seems a bit dim) but the immersion still does not work.
Any advice gratefully recived! Thank you.

 

[RMS]

if there is 230V present on both sides of the element then it suggests there is a break in the neutral conductor. The most likely place would be the switch.

If you feel up to it then you could test the switch using a voltmeter or polarity tester or you could isolate the power and join the wires together (by-pass the switch). You may find the wiring melted out when you remove the switch (loose connection).

I take you have no time clock?

The only other place could be the Neutral connection in the consumer unit but in my experience the problem is either in the immersion element head or switch(s) controlling the element.

I wonder if the engineer checked for a secondary stage cut-out within the element head?

 

[HERTS P&D]

Has the immersion tripped?


Can you post a picture of the immersion with the cap (top) off.

MAKE SURE THE POWER IS TURNED OFF.

Andy

 

[bertieshaw]

Thanks for suggestions to date. I'm not at home over the weekend so will follow up the comments made on Monday and report back!

 

[bertieshaw]

if there is 230V present on both sides of the element then it suggests there is a break in the neutral conductor. The most likely place would be the switch.

If you feel up to it then you could test the switch using a voltmeter or polarity tester or you could isolate the power and join the wires together (by-pass the switch). You may find the wiring melted out when you remove the switch (loose connection).

I take you have no time clock?

The only other place could be the Neutral connection in the consumer unit but in my experience the problem is either in the immersion element head or switch(s) controlling the element.

I wonder if the engineer checked for a secondary stage cut-out within the element head?

Thanks for you comments/advice so far.

Have checked the main switch (visually) - everything appears to be OK with no loose connections.

As mentioned on my original post I have noticed that since the BG engineer's vist the neon light on the switch DOES now come on (didn't before) but the immersion is still not working.

Testing the switch with a voltmeter is a bit too technical for me.....I have in the past noticed (when the immersion was working) that the switch unit did get quite warm - is this normal? Would it be worth replacing the switch?

To confirm no time clock involved.

Unfortunately can't answer whether engineer checked for secondary stage cut-out

 

[bertieshaw]

Has the immersion tripped?


Can you post a picture of the immersion with the cap (top) off.

MAKE SURE THE POWER IS TURNED OFF.

Andy

Can't see any trip switch on the immersion unit itself ??

Photo attached as requested.

Untitled

• bertieshaw
• 11 Jun 2012
• 1

Hope this helps

 

[RF Lighting]

There is no thermal cutout on that immersion heater. If you have a plastic header tank then you must have one fitted. If it is a metal header tank it is still a good idea to have one fitted.

Your switch should not warm in normal operation. It might be worth replacing this as it does sound to have been behaving a bit abnormally. I am not guaranteeing that this will cure the problem, and if not then I think it's electrician time, but it's worth a go.

When you remove the old switch, make sure all the copper ends are bight and shiny metal. If they show any signs of heat damage they will need to be cut away to bright wire, which may mean extending the cable.

Make sure you isolate the power at your fusebox before you start. If you are unsure then turn off ALL main switches at your main intake / meter position.

 

[bertieshaw]

New switch now fitted - neon goes on and off OK but immersion heater still not working.
Just a thought (and in the absence of any circuit testing tools) .... if I were to disconnect the wires from the immersion heater and connect them across a light fitting/bulb holder, then if the light bulb came on and off OK would this prove that the wiring circuit was OK and that the fault was in the immersion heater unit itself??
Thank you

 

[HERTS P&D]

My advice is to fit a new immersion. We can tell you what to do if you need help.

Andy

 

[bertieshaw]

My advice is to fit a new immersion. We can tell you what to do if you need help.

Andy

Thanks Andy

It may well be the best option. I've read advice on how to replace on other posts so am reasonably confident I can have a go if necessary!!

The immersion heater unit (and its replacement) are covered on my Service Contract with British Gas so if it is the immersion unit they should replace it under this cover. As mentioned in my original post the BG engineer said he thought it was a problem with the circuit and not the immersion element so would not replace it at that stage. Hence I've been trying to rule out other problems so I can go back to BG and tell them with some confidence that it is the immersion unit....

Thanks again for your advice

 

[securespark]

Have you tried connecting a socket on the end of the IH flex and plugging in a vacuum to see if it works? Or at least using a plugin tester like a Martindale to check correct operation?

If you have correct operation, it must be the IH.

Another thing to think about is if you have BG cover for the IH, do you have cover for the leccy supply to the IH?

Maybe if you do, they could check the supply to the IH as well as the heater itself.

 

[bertieshaw]

Have you tried connecting a socket on the end of the IH flex and plugging in a vacuum to see if it works? Or at least using a plugin tester like a Martindale to check correct operation?

If you have correct operation, it must be the IH.

Another thing to think about is if you have BG cover for the IH, do you have cover for the leccy supply to the IH?

Maybe if you do, they could check the supply to the IH as well as the heater itself.

Problem solved! BG has now replaced the Immersion Heater element under my Service Contract, having convinced them that I'd checked the wiring circuit for faults.....

Many thanks for advice and comments from everyone who responded to my post. Appreciated !!