Help - Bizzare Immersion Heater Problem :S

[Jinxed]

Hi All

Got a bit of a bizarre problem that Id appreciate some help with
Ive been through the WIKKI & FAQ's and nothing seems to fit exactly, hence this new post.
The problem is with my immersion heater.
It started yesterday (22/08/07) when all of the electricity in the house suddenly went off
We managed to isolate the problem to the Immersion Heater by tripping the switches on the circuit breaker.
I have left the one to the Immersion Heater switched off.
The Immersion Heater is a Hercal one, installed in the airing cupboard, and I beleive it to be 4 years old.
It has an electric cable running to it from a switch on the wall (also in the airing cupboard).
The cable runs from the switch on the wall to the top of the Immersion heater and is covered by a hexagonal cap.
Ive removed the switch from the wall, hoping to find a hidden fuse that I could replace, but unfortunately there was no hidden fuse.
All of the wires in the switch are securely attached.
I took the hexagonal cap off the top of the Immersion Heater, which left exposed what I beleive to be a rod that goes in to the Immersion Heater. (God you can tell Im clueless regarding stuff like this )
On top of the rod there was a blue temperature dial - the thermostat I presume ?
All of the wires attached to the top of the rod are secure, and all seem to be in good condition - ie they dont look like they have burnt out or anything.
On the outside of the Immersion Heater is what appears to be another thermostat?
This seems to be simply strapped to it, and has a cable running from it to a junction block.
Also running in to the junction block are 2 other cables.
One of these cables runs from a device that has Grundfos written on it - the pump I beleive?
The other cable runs from a white box that contains some sort of pcb, and is attached to one of the pipes - Not got a clue what this is or what its for .
Right - For the main problem
After I had completed my checks, I flipped the switch on the circuit breaker to on for the Immersion Heater.
Once again all the electric to the house turns off.
Turned the switch on the Circuit Breaker for the Immersion Heater to off, turn everything else back on, and all runs ok.
The Immersion Heater feels hot.
The pipes around the Immersion Heater feel hot.
The radiators feel hot.
The really bizarre thing is we also have hot water ? !!!
Reading through the other posts I first thought it could be the element that had gone, but surely if the element had gone, we wouldnt get hot water?
Anybody any ideas?

Thanks in advance

Kris

 

[gas4you]

Water is being heated indirectly by boiler I presume Immersion element has gone and is either short circuit or tracking to earth.

 

[JohnD]

also, i think you are saying Immersion Heater when you mean Hot water Cylinder

A hot water cylinder

An Immersion Heater

the cylinder can be heated either with the electric immersion element, or by the gas boiler, so you can get hot water using one if the other has failed. the immersion heater should be turned off on days when the boiler is turned on, since gas is cheaper.

the thermostat strapped to the side of the cylinder controls heat from the boiler to the cylinder.

 

[Softus]

Please could you post your problem again, describing your things according to JohnD's images and labels, and using about one tenth of the words?

 

[Jinxed]

Lol - Softus

Many thanks for the quick responses

I have a water cylinder in the airing cupboard
It looks like an Immersion Heater goes in to the top of the water cylinder.
My circuit breaker tripped out on the 22nd
Managed to isolate the problem to the switch on the circuit breaker to the one marked Water Heater
Checked the switch in the airing cupboard that leads to the top of the Immersion Heater.
All seems ok
Turn on Immersion Heater Switch and switch for water heater - all electric to the house goes off.
Not sure how to resolve the problem

Cheers

Kris

 

[Softus]

All immersion heater elements eventually corrode and break down. Some of them then draw too much current and trip the circuit breaker (or blow fuse, or whatever). This is what yours has done, or I'm a monkey's uncle.

The remedy is to replace the element. This is mainly a plumbing job, and has been well covered on the relevant forum. Ask here again if you can't find a sufficiently instructive topic.

 

[Agile]

Get someone to replace the immersion heater element!

We used to do that for just £48 some while ago but after some really problematic ones we have stepped up our price to be more in line with others.

Now we charge £106 inclusive for a top entry replacement and £116 for a top side entry element and £126 for a bottom side entry and £146 for two side entries.

The difficulties come from draining the system and turning off the feed. Valves can be jammed, drain cocks seized, drain cocks leaking after opening and nowhere to drain the cylinder into. On one with only a toilet to drain into we had to empty the last 500 mm into a bucket then a dish as the level fell.

Tony

 

[solo]

Ha ha. I'm charging £115.00 (no VAT) to replace an immersion tomorrow and I'm nowhere near London. Don't know how you get by on those prices?

 

[Softus]

Get someone to replace the immersion heater element!

Good idea. It's pure genius how you come up with them.

We used to do that for just £48 some while ago but after some really problematic ones we have stepped up our price to be more in line with others.

Do you think the OP knows who "we" is supposed to be, or why you're posting your charges?

The difficulties come from draining the system and turning off the feed. Valves can be jammed, drain cocks seized, drain cocks leaking after opening and nowhere to drain the cylinder into. On one with only a toilet to drain into we had to empty the last 500 mm into a bucket then a dish as the level fell.

These are things that an amateur (or a radio engineer) would regard as problems, but a plumber wouldn't. And who in their right mind would drain a cylinder from its drain cock?

 

[Agile]

You people in Albania have to realise that many prices in London are a lot lower than in the sticks.

My hairdresser in Warwickshire charges me £9.80 but a Polish haircut in London is just £5 or even £4 on quiet day if there is another barber within 100 yards!

Tony

 

[Mystic Martha]

Ha ha. I'm charging £115.00 (no VAT) to replace an immersion tomorrow and I'm nowhere near London. Don't know how you get by on those prices?

I do.

 

[Agile]

And who in their right mind would drain a cylinder from its drain cock?

If they are not meant to be used for draining why do they teach students to fit them in the colleges?

For that matter why do they call them drain cocks?

Where do you drain cylinders from?

Tony

 

[Softus]

If they are not meant to be used for draining why do they teach students to fit them in the colleges?

I don't have the foggiest. Why don't you ask the people who teach students that?

For that matter why do they call them drain cocks?

Because they are drain cocks. I can hardly believe you asked.

If you're into investigating misnomers then you should reconsider the name "Agile".

Where do you drain cylinders from?

Whatever the quickest place is - the DHW outlet, the cold feed, whatever. If it's a top-mounted IH change then the IH hole. If it's a scrap cylinder then cut off the top with tin snips. Anything but a drain off cock - they hardly ever seal when you need them to and won't let anything much through if they're old.

 

[Jinxed]

Thanks all for the response's

So it sounds like the element of the Immersion Heater has definately gone

Is there any reason why I shouldnt just change the Immersion Heater?

Cheers

Kris

 

[Softus]

So it sounds like the element of the Immersion Heater has definately gone

Yes.

Is there any reason why I shouldnt just change the Immersion Heater?

No reason. That's what you should do. Get an Incaloy one that is more resistant to corrosion.