immersion heater problem

[malp]

Hi I have a immersion heater with 2 elements 1 for economy 7 at the bottom and another at the top. They are both connected to 2 switches with led lights and on off switches. The led for the bottom element does not light up however nothing has tripped at the fuseboard. The water is not getting hot on economy 7 so does anybody know does this sound electrical or do I have to replace the bottom element.

If I do is this a hard job and any advice would be most welcome.

Thanks

 

[JohnD]

If the neon in the switch does not light it might be:

-Failed neon
-Failed switch
-Failed cable
-Failed fuse or MCB at "fuseboard".
-Failed off-peak timer
the immersion might or might not be faulty but it would not cause the neon to stop working.

If you can lay your hands on a multimeter (not a neon screwdriver!) and are confident to work with electrical items you can work out where the fault lies before replacing one of the parts that is not faulty.

If you can post some photos of the immersion heater switches; the timer, the fusebox and meters, we may have more ideas.

When did the off-peak immersion last work, and how old is it?

 

[gas4you]

sorry to sound too basic, but are you looking for the neon to light during the day or when power is to it during the night economy 7 timer period

 

[malp]

it last worked properly a cpl of weeks ago. now i get lukewarm water unless i turn on the top element.

No the neon has stopped working full stop....

 

[JohnD]

...i get lukewarm water unless i turn on the top element.....

Do you mean the bottom element is working, but not at full power? Or is it not working at all?

Is the cylinder heated by any other means (e.g. gas boiler of coal fire)?

 

[malp]

I think i am getting lukewarm water from the bottom element

 

[gas4you]

perhaps luke warm water is result of upper immersion. hot water could pass heat very slightly downwards.

 

[Paul Barker]

Yes, John's first post is your answer, get an electrician.

 

[kevnurse]

I don't think its that difficult. You should trip the mcb and open the switch. You will probably see a molten mass of plastic and copper. reason: Its a 3Kw(?) immersion heater switch, which means that current passes over temporary contacts, which eventually get pitted and start to cause sparks and heat and then the continuity of the switches breaks down and no current passes through the unit. The mcb doesn't sense a short so it remains made.

I found this very problem only a few weeks ago.

The bottom immersion heater should have its own mcb, and if so I would replace the switch with an (un-switched) connection unit. There is no need for a switch on an Economy 7 immersion heater. The timer does the switching and if the householder wants to stop heating the water he can use the Imm Htr mcb or use the main switch in the CU if he doesn't want any CH or DHW.

 

[resq]

Could this be a case of the copper (element) failing. I had similar problems a couple of weeks back with my single element immersion tank. Got a plumber out as I couldn't remove the copper. Job done in 2 hours and £16 worth of parts