How close can a boiler flue be to a window?

[cascas]

Hi,

I am currently planning a kitchen lay out, which may involve replacing a combi boiler to a position next to a window. How close to a window can a flue be installed? If the window is constructed so only one side is opening, is this distance measured to the opening in the building (i.e fixed window), or the actual window opening? Make/Model of boiler is not determined yet, so cannot check MI instructions

 

[E4gas]

Check M I or viper book

 

[Mbear]

Usually 300mm if fan flued. This is from edge of flue to the rubber window seal.

Ie if the window is non openable at the flue end then it's ok but if the openable windows seal Is closer than 300mm then it's not ok.

This is for fan flued only, some balanced flue are 600mm dependant on chb kw size. Read the instructions, the distances can all be different

 

[smileyplumber]

check manufactures intructions as that is the overiding factual document

 

[ryangas]

Usually 300mm if fan flued. This is from edge of flue to the rubber window seal.

Ie if the window is non openable at the flue end then it's ok but if the openable windows seal Is closer than 300mm then it's not ok.

This is for fan flued only, some balanced flue are 600mm dependant on chb kw size. Read the instructions, the distances can all be different

Im pretty sure its from the center of the flue to the start of the opening i know not much difference and a little padantic but can sometimes make a difference that 35mm

 

[Mbear]

Im pretty sure its from the center of the flue to the start of the opening i know not much difference and a little padantic but can sometimes make a difference that 35mm

A building opening could be an unopenable window. A flue fitted close to this would be ok as their is no potential for danger as the window cannot open.

It's defo the window seal and edge of flue

 

[ryangas]

mbear are u not allowed to put web links on posts

 

[PlumbBobBob]

not usually when you have just joined

 

[ryangas]

thanks steve

 

[MattWeth]

As far as I'm aware, the Building Regulations take precedence. Manufacturers instructions generally just repeat what's in the regs and can't in any case be less stringent. Take a look approved document 'J' page 49:

Planning Portal - Part J (Heat producing appliances)

This is what your council building inspector will assess the installation against.

 

[AlexGas]

Im pretty sure its from the center of the flue to the start of the opening i know not much difference and a little padantic but can sometimes make a difference that 35mm

I'd say you measure it from the outside of the flue. It might be pedantic, but try to explain it to the Gas Safe.

 

[Heating-eng]

I'd say you measure it from the outside of the flue. It might be pedantic, but try to explain it to the Gas Safe.

This is correct.
The manufactures instruction will tell you what you need to know.

 

[AWheating]

yes you measure from the outside of the flue not the center/poc tube. if you use a plumage kit then it may be possible to fit the flue at 150mm away from the opening following manufactures instructions of course.

building regs requires that nothing is fitted within 150mm of the building opening meaning brickwork not window to ensure the structures strength is not compromised.

 

[Halesowen1]

AW is correct, it is 300mm from an openable window, but if it is to be not openable you can reduce to 150mm. 150mm is the closet you can be this is building regs not gas regs. Again it is to the outside not the centre of the flue, so you must measure to the closest part. You could go to 150mm to an openable window if you want to fit a pluming kit.

 

[kirkgas]

i am fairly comfortable that the boiler will be a fan flued RS boiler so once confirmed then the flue at its nearest point needs to be at least 300mm away horizontally from any opening in the building, however the other dimension that seems to escape "hundreds" of re-assessment guys when they come to us is that any part of the flue must be at least 150mm horizontally from any opening in the FABRIC of the (with the fabric opening being where the window frame meets the brick) so it isnt simply a case of saying it can be near the windo as the opening is the other side of the window if that means it contravenes the 150mm rule at the dead light side

 

[kirkgas]

Im pretty sure its from the center of the flue to the start of the opening i know not much difference and a little padantic but can sometimes make a difference that 35mm

c'mon ryan think about it, it can NEVER be the centre of a flue it must always be the nearest point, eg you have a 100mm flue and measure from the centre, then go to another house that has a 150mm flue and again if you measure from the centre there is more flue within range of the window, however if you measure every flue from its nearest point then the diameter of the flue is irrelevant and therefore the volume of POC's getting to the window will always be the same

 

[Halesowen1]

Building reg's not Gas reg's maybe the reason all these numpties seem to find there way to you.

 

[kirkgas]

AW is correct, it is 300mm from an openable window, but if it is to be not openable you can reduce to 150mm. 150mm is the closet you can be this is building regs not gas regs. Again it is to the outside not the centre of the flue, so you must measure to the closest part. You could go to 150mm to an openable window if you want to fit a pluming kit.

i think there was a TB about this saying that you cannot fit a plume kit to try too legitimise an otherwise illegal flue, ie one within 300mm of the opening, as a plume kit is to divert legal POC's away to stop it being a nuicance, although we have a mantra of MI overrule everything, this is where the building regs need to be looked at in conjunction with the MI as it isnt enough to say the flue is fitted as per MI (ie 300mm from next doors window) IF next door say it is causing them distress, unless you mean using a plume kit to raise the terminal up and therefore cancel out the 300mm requirement as the terminal is now above the window

 

[Halesowen1]

But doesnt every M.I state that it is 300mm from an opening window, Door etc.
I may be wrong but I am sure none of them say window they say opening window.

 

[AWheating]

yes many manufactures will allow you to use the plume kit to raise flue away/above window and this allows you to have the flue/air intake at 150mm from opening.

 

[Halesowen1]

I have on many occasions. I had one 2 weeks ago, had only one place for the boiler, upstairs A/C, had to put flue out horizontal which was close to a window opening onto it as it was a huge 1 pane window that opened right out. SO I fitted a pluming kit and all was fine, no probs with clearances and no danger of POC getting in as I ran it 1m away.

 

[Dannypipe]

Don't know about you lot, but plume kit or not, I wouldn't sleep easily knowing there's a flue 150mm from my window. Or 300 if I'm honest. Yes we all have occasions when things are tight, and you have to fit within your legal limits. However I always try and make the distances between flue terminals and openings as big as possible. For my piece of mind.

I looked at a boiler late last year that conformed to all legal clearances. However due to the location of the window (about 350mm from flue terminal) and the front door, a wind tunnel effect was happening. Pulling POC's into the property.

I was called to repair the boiler, and complete a CP12. I advised the landlord to permanently seal off the window, which he did. Only then was I happy to sign it off. Despite the fact that another engineer who is more cavalier would have signed it off as it was.

In short, yes conform to the legal clearances, but also use your loaf, and ask yourself, would I go to sleep in that room, with that flue so close to the window? Would I let my children sleep in that room? If the answer is no. Then don't do it. Most people will be grateful for your integrity.

 

[kirkgas]

But doesnt every M.I state that it is 300mm from an opening window, Door etc.
I may be wrong but I am sure none of them say window they say opening window.

generally the MI will say 300mm from ay opening in a building eg a window or a door, but remember that also means the wee plastic slot vents you get between the vertical joints in bricks on facing brick walls, and also remember it tells you to comply with BS5440-1, which is where the 150mm to the fabric opening is found

 

[Halesowen1]

But the regulations are here to help us, A Corgi Inspector told me that if the flue was letting POC into the window it must therefore be open, then it will then be drawing in more than enough fresh air in to cancel the fumes. Makes sense I suppose.
Why would you not trust a pluming kit?? You can then take it metres away if you want.

 

[Halesowen1]

But they also say you can fit a pluming kit if you are less than the 300mm so who is correct?
I have fitted many and surveyed many on numerous contacts when less than 300mm from door or openable window and never had any trouble, all inspectors advise this rather than moving boiler position.

 

[Dannypipe]

Well, like I say, I use my gut on a lot of decisions. I have had my business partner say that I was being over cautious. Each to their own. I'm practically an insomniac as it is. The last thing I need is to be up at night worrying about a boiler I installed that day.

 

[Halesowen1]

But why would you worry? you have fitted the boiler to what is says, it is this distance for a reason.
Dont worry about flue being 300mm from a window where it might go into the room, how about a flueless fire?? If these are allowed I would never worry about a flue ever again.

 

[Dannypipe]

Here's a boiler I replaced last year. Concealed flue, running through the ceiling void. Various faults with the boiler (leaking HEX, and more). So when they asked me to replace it, I said I wasn't really happy about running a long concealed flue (with access panels) and then terminating the flue here. First photo shows the old boilers terminations (nice - not) then you can see up the shaft.This shaft is surrounded by windows into the various flats on all four sides. Where I took the picture from is a no mans land. Locked with a FB1 key, and used only to access the flues. Windows on all fours sides, and only about 8ft X 8ft.

I managed to convince the customer an electric flow boiler was a better option as it was a rented out, one bedroom flat. No more yearly CP12's and reduced servicing costs. Plus I don't need to worry that some one might be breathing fumes from a boiler that I installed.

 

[ryangas]

c'mon ryan think about it, it can NEVER be the centre of a flue it must always be the nearest point, eg you have a 100mm flue and measure from the centre, then go to another house that has a 150mm flue and again if you measure from the centre there is more flue within range of the window, however if you measure every flue from its nearest point then the diameter of the flue is irrelevant and therefore the volume of POC's getting to the window will always be the same

are you saying that to measure the distance of the flue from the opening you put your tape at the window edge and take it to the end of the flue and measure that distance ?

 

[Dannypipe]

Oh and for those of you who are keen eyed, you'll see the flue from the flat above, is practically next to the bathroom extractor fan. Doesn't matter to me that an extractor fan will blow air from the bathroom out, it's still an opening and therefore is also too close to the flue termination.

This block of flats (about 8 flats) has had 6 boiler ID's or AR's. Two from me. I've changed three boilers in the building in total. BG changed 2 others. Two of the boilers I changed to electric flow Amptec boilers. The other a WB with plume kit.

It was terrible, I found one flue which was patched with a coke bottle and duct tape. Another that run through the property above, and was spilling (in the little girls bedroom who lived in the flat above).

Nearly all Keston boilers, fitted by a (at the time) Corgi registered engineer.

 

[GrahamM]

The Manufacturer is king here as is mentioned time and time again.
Worcester allow you to have the flue 150mm from an opening as long as the Plume kit is fitted and exhausting at least 300mm from the opening.
I still do not agree with it myself and would always endevour to have the standard flue at least 300mm from any opening, but if was really no other option it may be done.

 

[Halesowen1]

Take reading from the edge of the brick not the glass, then to the outside of the flue in a straight line not on an angle to the outlet. Imagine the tape is up against the wall not angled out.

 

[GrahamM]

are you saying that to measure the distance of the flue from the opening you put your tape at the window edge and take it to the end of the flue and measure that distance ?

From the outside edge of the flue to the opening is the distance.

 

[Halesowen1]

Oh and for those of you who are keen eyed, you'll see the flue from the flat above, is practically next to the bathroom extractor fan. Doesn't matter to me that an extractor fan will blow air from the bathroom out, it's still an opening and therefore is also too close to the flue termination.

This block of flats (about 8 flats) has had 6 boiler ID's or AR's. Two from me. I've changed three boilers in the building in total. BG changed 2 others. Two of the boilers I changed to electric flow Amptec boilers. The other a WB with plume kit.

It was terrible, I found one flue which was patched with a coke bottle and duct tape. Another that run through the property above, and was spilling (in the little girls bedroom who lived in the flat above).

Nearly all Keston boilers, fitted by a (at the time) Corgi registered engineer.

Yes these are wrong, but a flue to M.I is ok.

 

[ryangas]

sorry to go back to this guys but think about it if you measure from the center of the flue it makes no difference what the diameter of the flue is you are always measuring from the same point