Lukewarm water from immersion heater

Can you remove the inlet or outlet pipe - probably easier than removing the heater - and put a borescope in?

Owain

it is probably the problem, that is if the thermostat isnt on it's way out, is it the type that sits in a pocket in the immersion heater head? usually a couple of squids to replace if you can't test it,

But as for getting the stuck element out, if it's resisting you, it'll most likely twist the tank if you try harder, i don't suppose there's another immersion heater boss blanked off higher up the tank?

Very, sometimes if you bang the side of the tank with your fist you will hear lumps of mineral deposit breaking off the sides and settling.

It isn't unusual for such heaters to be irremovable. They become embedded in a virtually solid lump of scale filling a quarter of the tank and either won't shift or break apart leaving the heating element in the scale. Sometimes you can remove the tank plus heater and try to remove the scale sufficiently to allow you to remove the heater but often a new tank and heater are required.

In message , Andrew May writes

There was quite a long thread on just this removal issue some while back. I guess a search on *immersion heater removal* for uk.d-i-y should find it.

There is a top-up heater halfway up the tank. I have switched thermostats but get the same so fairly certain that is it not the thermostat. The top up immersion is stuck as well otherwise I could go in through that one.

No. It already has a heater installed.

I think you are going to have to, as sooner rather than later if what you suspect is the case, the element will just go pop. The last one I did was not only lime scaled but twisted and distorted and the water got in due to the tube being breached in several places.

As for getting it out, well you could try some of the many helpful substances suggested on here in the past to free it, but in the end it might be that the tank is also so scaled that the only answer is a new tank. Depends how old it is and whether its good copper or some kind of alloy I suppose.

Hate the things but what can be done. Maybe we should sue the water companies?

Brian

Time to bite the bullet, then. Technically, you could take it out, fill it with descaler and hope that freed off the heaters, but enough descaler would probably cost more than a new tank and heaters, especially by the time you take the scrap value of the old tank into account.

From what I've heard use a box spanner rather than ring and gently try tapping the thing tighter as well as looser. Also do this inital loosening with the tank full as the weight of water tends to support the tank but don't get carried away, once it's "given" stop and drain...

I guess that the problem is going to be to find a matching tank with the inlet and outlet in the same place. The existing one was made by Albion and looks like it is part of their AquaPak

I'm a bit confused! The product in this link appears to be vented, whereas you said yours was unvented. [I wasn't aware that anyone made unvented cylinders out of copper - I thought they tended to be stainless steel].

So which *is* yours?

Ooh, you're right, I did say unvented. I meant to say vented. Just basic electric water heating in a 1-bed flat.

I have a box spanner - with a tommy bar. It fits but does seem a bit sloppy. Were older immersion heaters an imperial size? I have already had to source 6" tiles for the bathroom.

I believe plumbers have learned the art of making *new* bendy bits of pipe. ;-). Even I can do it if I have to.

Even more when you add in a water softener but that would be more of a long term investment.

Tim

You could drain the cylinder and then heat up immediate around the immersion heater with a blow lamp. Put spanner on and give it a good belt.

If this is due to massive scaling, the max temp its reaching will have fall= en very slowly over years. Does that fit?

Another possibility is a high resistance connection thermally close to the = thermostat, resulting in the stat opening prematurely.

Elements that have corroded through tend to cycle on and off, as there's of= ten excess current heating the stat up, but they reach the correct final te= mperature ok.

And some odd ideas to chew over...

A couple of times I've wondered about applying an external wrap of resistan= ce wire (on glassfibre tape) and driving it with LV to heat a cylinder. 2 m= icrowave transformers with primaries in series and a pc fan would likely do= it, if you limit each one to around 750w output. With an SS cylinder you c= ould omit the wire.

Another possibility is converting to mains voltage electrode heating. The r= egs explain how to do this legally, its common practice in industry, and en= tirely safe if done correctly.

NT

Assuming it is limescale, why not buy a tub of Fernox DS3 descaler (about £20, and enough to make hundreds of litres of descaler), turn the water off, open a tap to release the pressure in the expansion vessel, and then remove the pipe from the top connection, pour in some of the DS3 and leave it overnight. (you can apply some heat with the immersion heaters to speed it up). Then drain, and refill.

This was one person's solution to that:

If your IH is modern,it will have an additional overheat device. If it is scaled up, this could be operating.

Solution is to remove IH and clean it up. Also think about a water softener.

Needs doing pronto, IH could be damaged by this.

To remove heater, saw out gasket with a hacksaw blade. Comes out a lot easier.

You may say its safe, sounds bloomin lethal to me!

Brian