Leaking immersion heater on unvented system

[liverplum]

Hi.

The top immersion heater on the unvented cylinder is leaking slightly. It's surrounded by limescale as we are in a very hard water area. it's a brand new fitted flat and apparently this problem has occured in other flats and refitting the heater has solved the problem as it has presumably been badly fitted at installation.

Can I just turn everything off and shut all the supply down, drain, remove and refit?

Thanks in anticipation.

 

[advancedplumber]

yeah, pretty much. but is the unvented cylinder made of copper or stainless steel be aware that if u take a stilson or more appropiately an immersion heater spanner to it then it could be extemely difficuit to remove the old one. u can try and take a blow lamp to create expansion between the heater and the cyinlder but in the case of a copper cylinder i have seen the heat making the cylinder softer (and copper is a soft metal to start with!) and the whole top of the cylinder just twist and even split as u apply focre to try to loosen it. most unvented cylinders nowadays r stainless steel and have a lifetime (25 year) warrenty. it could be worth ringing the manufacture.

 

[liverplum]

Thanks for the response

It is a stainless steel one and the immersion doesn't look too well in there so hopefully it should come out without too much trouble.

When I refill the cylinder do I need to watch out for anything in particular or will it just refill itself until its full?

 

[seco services]

you may be able to just nip it up abit.

 

[liverplum]

you may be able to just nip it up abit.

Sorry seco, what do you mean by nip it up exactly?

 

[advancedplumber]

top tip. when ur at the supplier getting the new immersion get urself a tub of boss white. its a thick creamy paste/ compound. apply this around the new fibre gasket that seals between the immerion and the cylinder . some say boss white breaks down the fibres in the fibre gaskets and causes leaks but take my word if u use this you'll nver look back. apply it to rings on compression fittings aswell for leak free joints

 

[Paul Barker]

top tip. when ur at the supplier getting the new immersion get urself a tub of boss white. its a thick creamy paste/ compound. apply this around the new fibre gasket that seals between the immerion and the cylinder . some say boss white breaks down the fibres in the fibre gaskets and causes leaks but take my word if u use this you'll nver look back. apply it to rings on compression fittings aswell for leak free joints

You are quite right the only problem is it isn't wras aproved. Use an equivalent such as Jet blue.

 

[kevplumb]

top tip. when ur at the supplier getting the new immersion get urself a tub of boss white. its a thick creamy paste/ compound. apply this around the new fibre gasket that seals between the immerion and the cylinder . some say boss white breaks down the fibres in the fibre gaskets and causes leaks but take my word if u use this you'll nver look back. apply it to rings on compression fittings aswell for leak free joints

You are quite right the only problem is it isn't wras aproved. Use an equivalent such as Jet blue.

right on paul boss white sets like concrete

 

[holty]

whats the cylinder make as most immersions are factory fitted and could be under warrentry.not 25 years though.but most unvented give a warrentry on parts.

 

[clf-gas]

Would you not need the unvented ticket to drain, repair and re-commission an unvented cylinder

I dun kno

 

[oilman]

Would you not need the unvented ticket to drain, repair and re-commission an unvented cylinder

I dun kno

Not much point, in most cases I've seen, the installer didn't have one.

 

[johnfox]

should still be under some gurantee.
probaly no grease on O ring during installation or not fully tightened.
you could take it out and apply water grease under and over the O ring and on the threads.
check o ring is not damaged and all mating surfaces are smooth.

 

[JohnD]

I am just a householder

it seems to me that with immersion heaters the big problem is that old ones get stuck and you can't get them out (they don't last forever)

so Boss White or similar is going to make it even more difficult.

Can't PTFE tape be used on the threads to prevent then seizing? and silicone grease or something on the washer (which is supposed to be the watertight seal)?

I have seen LSX used on threads and seal but suspect that would stick them together.

 

[mickyg]

I think make/model of cylinder might be useful. some come with traditional fibre washers, but some more modern units have a rubber o'ring. best to make sure to get the right advice

 

[advancedplumber]

some folk on this site r quite petty when it comes to 'do this and never do that.' at the end of the day, you won't be drinking the water out of the cylinder. boss white has been around for years and used by most plumbers i know. and in recent times manufactures have made aternatives for potable (drinking ) water, ie boss green, like i said , u won't acually be dinking the dam water from the tank and when was the last time u heard of someone dieing or becoming ill from boss white ingrediants r liniseed oil and putty. very toxic indeed