How much to buy and fit new thermostat for immersion?

downshifter

My immersion heater water is getting far too hot, I asked an electrician to look at it a while ago and he turned it down, and said it was fine, which I'd already done previously, obviously! Sometimes it comes out at a reasonable temperature, at other times it's absolutely boiling, I'm sure I could make tea with it. And I can hear it in the pipes. As it's an intermittent fault I can see that if I call out an electrician again it will behave itself when he's here and start boiling immediately he leaves! So I'm assuming it's the thermostat and the best thing would be to replace it totally.

Can anyone give me an idea of how much this is likely to cost? It's the sort that just heats the top of the tank, just enough for washing up etc in the summer. In winter the coal fire and oil heating heat the water - and it's never too hot with those - the immersion is never used. At the moment I just put it on when I need hot water and immediately turn it off when I've finished, I'm too scared the thing will explode if I leave it on. However it's on at the moment and nice and quiet and the water is a sensible temperature. Your thoughts please. Am in rural north midlands.

Thanks very much

DS

DVardysShadow

The Thermostat is very cheap, £10 would probably cover it. Fitting is half an hour.

As it's an intermittent fault I can see that if I call out an electrician again it will behave itself when he's here and start boiling immediately he leaves! So I'm assuming it's the thermostat and the best thing would be to replace it totally.

Agree and an electrician should take an instruction to replace.

The immersion cylinder should have a top vent into a loft tank, so there is no real prospect of it blowing up.

ormus

stats are very cheap. about 10 to 15 quid.
fitting is a simple job.
http://diydata.com/problem/immersion/immersion_heaters.php

vaio

DVardysShadow wrote: »

The Thermostat is very cheap, £10 would probably cover it. Fitting is half an hour.........The immersion cylinder should have a top vent into a loft tank, so there is no real prospect of it blowing up.

Yep, it won’t blow up but the steam rushing up through the pipes does make it sound scary.

Fitting a new ‘stat is about on a par with rewiring a plug but they do come in different lengths so take the old one out first and measure it.

11’’ heater & stat is £11 and 27’’ version is £12 both from your local friendly screwfix outlet. At those prices buy a complete unit and keep the heater as a spare

wallbash

As previous poster have said ... cheap and easy to replace .

BUT ( why is there always a but )

The immersion cylinder is made of cheap thin copper
there is always ( because its done on an old tank. which has not been played with for years) a risk that removing the old 'stat' will damage the thread on the cylinder.

So most ( or all ) plumbers will say that they will try but the risk to the cylinder will have to be carried by the householder!!

downshifter

wallbash wrote: »

As previous poster have said ... cheap and easy to replace .

BUT ( why is there always a but )

The immersion cylinder is made of cheap thin copper
there is always ( because its done on an old tank. which has not been played with for years) a risk that removing the old 'stat' will damage the thread on the cylinder.

So most ( or all ) plumbers will say that they will try but the risk to the cylinder will have to be carried by the householder!!

Oh dear now I'm confused - is it an electrician or a plumber I should be phoning? It was put in around 7 years ago by the landlord (it's a rented house) but the rules have changed since then and I assume it isn't one of those things that can be done on a diy basis any more.

Thanks for the info, it's much cheaper than I thought, thank goodness.

DS

tfspark

wallbash wrote: »

As previous poster have said ... cheap and easy to replace .

BUT ( why is there always a but )

The immersion cylinder is made of cheap thin copper
there is always ( because its done on an old tank. which has not been played with for years) a risk that removing the old 'stat' will damage the thread on the cylinder.

So most ( or all ) plumbers will say that they will try but the risk to the cylinder will have to be carried by the householder!![/QUOTE

I believe that you are talking about the complete immersion heater and not just the thermostat.
follow the link in post #3 and you can see that the t'stat just looks like a rod that slides into the immersion heater itself.
No need to disturb any threads and definitely an electrician required.

vaio

downshifter wrote: »

Oh dear now I'm confused - is it an electrician or a plumber I should be phoning? It was put in around 7 years ago by the landlord (it's a rented house) but the rules have changed since then and I assume it isn't one of those things that can be done on a diy basis any more.

Thanks for the info, it's much cheaper than I thought, thank goodness.

DS

If it's a rented house then it's your landlord you should call rather than an electrician. Mention the fact that the heater is filling the loft with steam and all the condensation/rot possibilities that follows from that and I’d have thought he’d get it sorted pretty sharpish especially as it’s a cheap & easy repair

baldelectrician

There is a new type of stat for immersion heaters

These have a second (over limit) cut out to prevent the cylinder from boiling up causing a burst cistern in the loft

These are slightly more costly, but they save a life

See HERE

vaio

Yep, and they are compulsory now. I'm pretty sure you can't even buy the old sort any more

wallbash

I believe that you are talking about the complete immersion heater and not just the thermostat.

Sorry , yes I was .

In my defence I would always do a complete swap. if the thermostat is on it way out , what condition will the rest be in???

And therefore I would recommend a plumber , swap the lot:j