Immersion Element

boydkev

I am having a problem with the Element for the immersion, Recently we had to get it replaced due to corrosion and also got a water treatment system but since then we have gone through 2 element as they keep failing.
Could this be caused by the Water pump/tank in the attic being wired from the same circuit as the immersion?, We had the pumping system/New immersion Tank installed about 2 years ago. It seems to happen when the immersion is set to come on at 7.00 and it then trips the immersion fuse in the box.
This problem is starting to annoy me.

sky6

Possibly, They should really be on separate circuits. Also the Water Pump should be on a B type or motive power breaker.
Also if your in a hard water area you should have an Incoloy type element. Hard Water is very corrosive on normal Immersion Elements.

2011

sky6 wrote: »

Possibly

I don't agree.
Why would this cause an immersion to fail?

brightspark

Very soft water can corrode elements too (water likes to absorb materials)

You can also have problems if using a stainless steel tank (different metals don't get on well with each other)

Or you could simply have got some bad elements.

Don't see how you can blame the water pump!

@Sky6, the OP has stated he has a water treatment system installed, my guess would be a water softener, so it's unlikely that he still suffers from hard water.
(I have difficulty understanding your first paragraph too, can you explain it more?)

sky6

Yes but not to the same extent of hard water. I've seen 2 inch copper completely solid after 18 months in hard water. I've also seen other parts of the same pipework eaten through.
Yes the op has a filtration system now but the damage could have already been done. The walls in immersion elements
are extremely thin. It seems like he has either a lose connection an overload or a short.
Isn't it possible on start up that either the motor or Immersion is causing an overload on the Breaker. What else is also connected into the same breaker. ? Could the breaker be faulty.?
If I were the op I'd start by checking all connections on both unit's including the Board. ( make sure to kill all power first.) Then I'd check each unit separately to see if either is causing the problem alone. Then proceed from there.

2011

sky6 wrote: »

Isn't it possible on start up that either the motor or Immersion is causing an overload on the Breaker.

The OP has not stated that any MCB is tripping.

According to the OP the problem is with "Element for the immersion" which is "due to corrosion".

What else is also connected into the same breaker. ? Could the breaker be
faulty.?

There is nothing to suggest a faulty MCB.
It is permitted to connect a pump to the immersion MCB according to ET101:2008

sky6

I hear what your saying but I've just seen that that a new element was fitted so not corrosion causing the problem.
So what is causing the problem. If all equipment is ok then it's a wiring problem. So maybe a loose connection somewhere.
i know you can lump small pumps in with other things but I've never seen it as good practice. Because you can end up with the type of problems the op is experiencing. But maybe that's just me.
I can't see how you can dismiss the MCB so lightly. Only recently I had to replace one in my own house for tripping without reason. Replaced MCB with like for like problem solved.

2011

sky6 wrote: »

If all equipment is ok then it's a wiring problem.

It could be, but I very much doubt it. It is quite hard to make an immersion element fail with bad wiring (unless a far higher voltage is applied and that is not the case).


If I were a betting man I would say that the issue is corrosion, not wiring.

I don't think that we have enough information to come to any meaningful conclusions. If you read the 1st post carefully it does not say that the unit that had been installed recently failed, it say that 2 failed since the water treatment system was installed.

So maybe a loose connection somewhere.

This will not cause an element to fail.

i know you can lump small pumps in with other things but I've never seen it as good practice.

Why? They use very little power.

I can't see how you can dismiss the MCB so lightly. Only recently I had to replace one in my own house for tripping without reason. Replaced MCB with like for like problem solved.

Can you explain how an MCB would cause an immersion element to fail?
What information has the OP provided that points to a faulty MCB?

If the MCB is faulty then replacing the immersion element would not solve the problem.

sky6

I agree with everything you say. I've just read the ops thread again and he doesn't even mention an MCB he said a fuse. Perhaps he still means a breaker.
I've also just seen that it's two Elements in less than two years. That kind of rules out corrosion and leads me back to hard water as a lose connection shouldn't even cause Element failure. Unless the Elements are of very poor quality to begin with.
As you say without seeing the situation in person it's very difficult to know what the real culprit is.

Bruthal

Hard water will cause elements to overheat and split. The limescale insulates the element from the cooling effect of the water. This usually won't trip mcbs because the element heating conductor has enough impedance to not trip the mcb even if it shorts with the copper casing, unless the short occurs very near the live end of element. I never seen them trip mcbs when split.

But they trip rcbos or RCDs at the slightest amount of water getting in.

So its more through overheating than corrosion, that hard water damages elements.

sky6

That makes plenty of sense all right and could be the ops problem. The Element would act like an Anode in the cylinder.

boydkev

Thanks for all the feed back, We have ruled out the hard water as we have recently had the water retested and it was fine.
It is tripping the RCBO when the Immersion comes on, So i think this is where the problem is. We have had the wiring checked and it looks like this was where the problem was, Looks like there was a short somewhere and that is what was causing it to trip. Cant understand why it was not spotted during previous checks.
So fingers crossed it wont be happening again.

2011

boydkev wrote: »

It is tripping the RCBO when the Immersion comes on, So i think this is where the problem is.

This is a bit confusing because in your first post this statement suggested that replacing the immersion elements fixed the problem:

I am having a problem with the Element for the immersion, Recently we had to get it replaced due to corrosion and also got a water treatment system but since then we have gone through 2 element as they keep failing

A wiring error that was solved by replacing the immersion element would generally remain resolved.
Also I can not think of a wiring error that would cause elements to "fail".

Cant understand why it was not spotted during previous checks.
So fingers crossed it wont be happening again.

Not very well checked I would think.

Tuco88

Have you the lads with the long tails that like to snack on delecious T&E, have you a problem with the pump N to E fault is it on the same Rcbo? Like previously stated it's strange to see a wiring problem damage an element it's just like a giant resistor.

I had the unlucky problem where the copper sleeve that the stat slides into would fail. It would not trip all the time only when the the immersion was on for a bit, the steam would condensate in the connection box then trip. I would turn up and the connection box would be dry... What had me was why it was not leaking all the time, the pressure difference like when u pop a needle hole in a bottle of water?