Neon light on immersion heater switch.

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Hi all,
Our gas boiler failed a couple of weeks ago and are waiting for the plumber to fit a new boiler so we were relying on the immersion heater for hot water. However, this morning when I switched it on, the neon light did not light up and no hot water. The immersion heater is on its own circuit (fuse is ok). The switch with the neon light is in the kitchen. There is also a switch (no neon light) in the airing cupboard adjacent to the tank. Obviously both need to be on for the immersion to work. What I would like to know is:- Does the fact that the neon light is out indicate that there is no power being passed to the immersion heater or could it mean that the immersion heater has failed? What I'm thinking is that the neon is on the supply to the immersion and that the switch is faulty.(it is very old - probably since the house was built in 1960 - hardly used at all since 1980). Advice needed to see if I need an electrician or plumber or just fit a new switch.
 
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The fact that there's no hot water suggests that there's no power to the element. Those neon lamps do have a habit of failing but if there's no hot water, it's an effect rather than a cause. Immersion heaters do indeed have a habit of failing too and if nothing has changed on the circuit, then it's probably a good place to start fault finding. If you're confident with (and indeed own) a multimeter, you could test the voltage across the immersion heater terminals. If you're confident with (and indeed own) the appropriate spanner, you could change the immersion heater too or call a plumber.
 
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If you're confident with (and indeed own) a multimeter, you could test the voltage across the immersion heater terminals.
A good start, and the voltage can be tested at the consumer unit, and at the other switch too.

If you're confident with (and indeed own) the appropriate spanner, you could change the immersion heater too or call a plumber.
Well, that's a big and complicated leap. I would want to properly test all of the electrical circuit issues first before making the assumption that the heater itself is faulty!
 
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If you're confident with (and indeed own) the appropriate spanner, you could change the immersion heater too or call a plumber.
Well, that's a big and complicated leap. I would want to properly test all of the electrical circuit issues first before making the assumption that the heater itself is faulty!

Yes, sorry, what I mean was, "if you establish that the immersion heater is faulty..."
 
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It does sound like you need to check the screws securing the wires are tight in the switch with neon and then replace it.

20a switch I expect
 
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I do not have a multimetre tester. What I need to know is:- If all the switches and circuits are OK and the immersion heater is faulty would the neon light (assuming that it is not faulty itself) still be on? or if the immersion heater has failed and all the switches and circuits are OK would the failure of the immersion heater cause the neon light to go out?
 
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If the fuse is OK, and switch and all the connections are OK, the immersion heater failing would not make the neon go out.
 
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Has the immersion ever worked? Is it connected to the off peak supply?
 
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Yes, the immersion has been working OK since we started using it exclusively since the CH boiler failed 3 weeks ago.
We have no off-peak supply.
 
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Have determined the problem is with the switch with the neon. Checked the connections. One was not tight. After tightening when power switched back on the neon light flickered. After operating the switch numerous times managed to get it working again. Suspect the contacts are pitted.
Have purchased a new switch, but will leave it as is, until the new boiler is installed and then replace.
Thanks all for advice.
 
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Have purchased a new switch, but will leave it as is, until the new boiler is installed and then replace.
Perhaps before then somebody here will have posted a photo showing what can happen to a switch which has damaged contacts, and/or has a damaged cable connected to it, and you'll decide that you'd rather replace yours and cut the cable back to bright, soft copper before that happens to it.
 
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Are you sure that the (old and) new switches are suitable, i.e. rated to suit the immersion?
 

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