sleeving flue on boilers!!!

[beesley121]

Hi guys,

just been on a course today ready for my ACS exams in a few weeks.

tutor said and showed me in a magazine that it is now a requirement that you now have to sleave the flue on a boiler to make it easier to remove and also something to do with the metal of the flue expanding when hot, thus could cause problems to the skin of the biuilding

as anyone elese heard of this?? This is defo true as i read it first hand but what i want to know is what the hell would you use to line the flue??

 

[GrahamM]

Are we talking about a room sealed fan flued boiler here?
Do not recall any MI's stating flue must be sleeved. Only done few installs but never used a sleeve. If it was mater of course would it not be included in flue kit?

A balanced flue system may require sleeving going through a combustible cavity, but that is because of the more heat generated by this system.

Replaced a few flues and never had much problem removing the old one.

 

[kirkgas]

it will refer to flues going through a timber framed building, there is a document relating to it, cant remember the number, sorry, look in any boiler MI's you have lying about it will quote the document in there

 

[GrahamM]

Ahh. On the button kirkgas. It's IGE/Up/ Ed 2 it mentions none combustible sleeve for timber frame buildings.

 

[beesley121]

i understand that there is a need to sleeve a flue through a timber building but this 'new' requirement was to sleeve flue's through masonary walls as i remember one of the other lads on the course lauging about the size of the hole he is going to have to start making with hhis core drill when h already drill big holes anyway and how the customers might not be happy. im sure it was in the gas safe magazine either this month or last months. if no-one knows anything about it, i will find out of the tutor tomorrow what exactly it is

 

[kirkgas]

i understand that there is a need to sleeve a flue through a timber building but this 'new' requirement was to sleeve flue's through masonary walls as i remember one of the other lads on the course lauging about the size of the hole he is going to have to start making with hhis core drill when h already drill big holes anyway and how the customers might not be happy. im sure it was in the gas safe magazine either this month or last months. if no-one knows anything about it, i will find out of the tutor tomorrow what exactly it is

i will be interested to hear what the outcome is on this, and cant really see it being a reasonable requirement or help to fit a sleeve in a brick wall

 

[beesley121]

yep, asked trainer today. it was in the latest gassafe magazine. you have to now sleeve all flue, even ones going through brick, breeze/concrete block. not read the the mag myself but he told me its to do with 'thermal expansion'. that is all i know on the matter. he said you gas safe lads should be able to look it up on the gassafe website so take a look and let me know in more detail. thanx

 

[kirkgas]

ask him to show you the article and tell me which page it is on so that i can have a look, i'm not convinced

 

[CMairiD]

Re Doc J, Page 32, Factory Metal Chimneys

Factory metal chimneys systems for gas
appliances where flue temperatures do not
normally exceed 250°C, the use of
twin-walled and single-walled flue
components manufactured to BS EN
1856-1:2003(5) and installed in accordance
with BS 5440-1 are acceptable. Where a
factory-made metal chimney passes
through a wall, it should be sleeved to
prevent damage to the flue or building due
to thermal expansion.

 

[beesley121]

thankyou CMairiD. My tutor is sh*t hot when it comes to gas and legislation. He's got gas written through him like a stick of blackpool rock.

I knew he would be right!! what i wanna know know is what the hell are we going to sleeve it with?? surely the manufacturers are going to have to supply something now with their flue kits

 

[Toddyplumb]

So its to prevent damage , so a whole load of AR coming up from the cowboys
Baxi multi flue fits inside soil pipe

 

[stevetheplumber]

not seen this but i think this is relating to conventional flues as a normal concentric flue is already sleved by virtue of the air duct

 

[archiedale]

yes steve, thats the conclusion i came up with, going to speak to the " in the know" tomorrow.

 

[beesley121]

yes steve, thats the conclusion i came up with, going to speak to the " in the know" tomorrow.

let us know mate please what the position on this

 

[dontknowitall]

I reckon if you put the boiler and flue in the middle of the garden with pipes dug down around 100 metres that should please all those in authority. Some of these rules seem to be created just for the sake of justifying keeping the rule makers in jobs.

 

[moony]

not seen this but i think this is relating to conventional flues as a normal concentric flue is already sleved by virtue of the air duct

i dont think it will effect us installing domestic boilers much to be honest - very rare i come across a conventional flue anymore on any installations

 

[moony]

and it would just be classed as ncs on safety checks not ar

 

[Toddyplumb]

Disagree with NCS . It says the sleeve is to prevent damage due to thermal expansion . So if it is not sleeved and is left in use it may in the future constitute a danger to life or property AR. I disagree with unsleeved pipework being NCS aswell for the same reason . In the old CORGI book that was NCS as well

 

[CES]

not seen this but i think this is relating to conventional flues as a normal concentric flue is already sleved by virtue of the air duct

That would be my understanding, I dont think there would be much thermal expansion with a normal HE flue these days anyway, considering the exhaust part is mainly plastic.

 

[GrahamM]

thankyou CMairiD. My tutor is sh*t hot when it comes to gas and legislation. He's got gas written through him like a stick of blackpool rock.

I knew he would be right!! what i wanna know know is what the hell are we going to sleeve it with?? surely the manufacturers are going to have to supply something now with their flue kits

I would be a bit worried if my tutor was not clued up when it comes to legislation, that is his job at the end of the day. Pointless new legislation or not.

 

[russgas]

Hi, surely this only applies to non room sealed boilers! If manufacturers instructions dont say this then you dont have to sleeve them.

 

[Toddyplumb]

I have read the article now and I do not think it means concentric flues . Did anyone phone the Gods today ?

 

[russgas]

Some balanced rear flue fires require the flue to be sleeved.

 

[CES]

I think theres a bit of a misunderstanding between gas regs, standards and MI's going on here. MI's supercede all standards and I'm pretty sure that the standard this involves are only applied to flues normally found on a commercial system ( although I'm sure there will be the odd one). So as far as I'm concerned, unless the MI's state that a flue needs to be sleeved,or its written in the gas regs, I'm going to go with the usual practices adopted with a domestic install. I think theres been a bit of panic where its not needed, although its good we're being kept on our toes for a change.

 

[Toddyplumb]

I think its good we are talking about it as well . I prefer visiting the forum than Tech updates on gas safe

 

[moony]

Disagree with NCS . It says the sleeve is to prevent damage due to thermal expansion . So if it is not sleeved and is left in use it may in the future constitute a danger to life or property AR. I disagree with unsleeved pipework being NCS aswell for the same reason . In the old CORGI book that was NCS as well

if the rules stated last year you could put an unsleeved flue in, and then this year it says you need to from now on sleeve flues = then last years flue would be ncs and this years could be classed as ar i suppose as it was installed when the rule come out - this is just what i would do - may be wrong - but if something was installed the right way the year it was installed and then new rules come out stating it needs to be installed a different way then i just put ncs (not to current standards) which it isnt. If it hasnt been ar for the last 5 years its been in a landlord wouldnt see why it is now at risk because of new legislation - so would just ncs it.

 

[Billy Bob Bob]

i think its a load of ballocks,after all in this age of condensing the flues are plastic

 

[Toddyplumb]

Agree with all of that Moony. Agree with that Gas man , I dont think we are sleeving them.

 

[beesley121]

Spoke to tutor today, he says from what he can gather that this will be for metal flues only. so if the inner flu is plastic and the outer flue is metal. it has to be sleeved

 

[CES]

I would have thought that if the inner was plastic (the hot exhaust) and the outer metal (air intake) then it would not need to be sleeved as there would be no thermal expansion causing damage to the building which is what this is supposed to prevent? Or am i using common sense too much? Im in agreement with Gasman on this too.