Regs for combi boiler flue on house extension

[gunnag]

IM interested in finding out what the regulations are relating to fitting a new flue on an existing condensing combi boiler a heatline viso 24 plus.

My partner recently had a single storey extension built on the back of her house. Since the existing boiler was fitted onto the inside of a previously outside facing wall, the builder re routed the flue to exit through the extension flat roof.

The existing flue simply exited the boiler from the top and then turned 90 degrees horisontal to go through the wall and exhaust outside. After the extension was added, the builder modified the flue by adding a new 90 degree horisontal joint to the old outside wall and a 3m straight section paralell with the old outer wall before adding another 90 degree vertical joint so that the flue exits through the flat roof. The end of the flue is approx 30cm above the flat roof and 30cm from the existing outside wall.

The builder boxed in this flue arrangement to make it tidy.

Recently the boiler broke down and after calling a gas engineer we were told that this was an illegal installation. apparantly having a 90 degree vertical flue extension is against regs as well as having no inspection panel in the boxed in area.

Obviously we are upset as we thought the builder knew what he was doing and believed the council had inspected the works and passed it.

So the question is what to do next? We will go back to the builder and claim compensation for an illegal installation but we would like clarification on what the regulations state for flues. The extension has two velux windows which can be opened and also there is a window above the extension which can be opened. How far must a flue be away from these areas and must it exit from the roof or is a side exit an option?

All info welcome.

 

[ianmcd]

Contact the Gas safe register and lodge a complaint, they will inspect it and let you know if it was carried out by a gas safe registered engineer (doesnt sound as though it has been) I very much doubt if any gas safe engineer will want to get involved at this stage as GSR will not act on a complaint from another RGI but will act on a complaint from you as the customer

 

[CBF]

the work should have been done by a RGI not a builder unless he was gas safe reg it was illegal for him to touch the flue, can you take some pics of the flue & the windows & post em up

 

[RickMoore]

Assuming it's a 60/100 concentric flue it's too long now, and should have been upgraded to twin pipe to go horizontal and vertical. New Flues in Voids regs are specifit about flues being accesible for inspection.

300mm for the terminal away from the wall is minimum, and must be 1000mm min from an adjacent opening window.

 

[CBF]

1000mm min from an opening window.

not below a velux it's not which is why i said post some pics so we can see where it is

 

[ALEC1]

Obviously we are upset as we thought the builder knew what he was doing and believed the council had inspected the works and passed it.

Why would a builder know anything about boilers, heating and gas regulations...

 

[RickMoore]

1000mm min from an opening window.

not below a velux it's not which is why i said post some pics so we can see where it is

Yep my bad, my post edited so it's correct.

 

[CBF]

keep hitting that edit button Rick

 

[RickMoore]

keep hitting that edit button Rick

RTFM m8, page 17

 

[CBF]

if the flue is along side or above a velux it's 600mm

 

[RickMoore]

if the flue is along side or above a velux it's 600mm

Either of those is adjacent atleast in my interpretation which requires atleast 1000mm f
From the terminal.

 

[CBF]

the 1000mm you are ref to is R in this pic


http://postimage.org/

 

[RickMoore]

You started out with below a velux, then went to above or to the side of. Any which way it's adjacent to an opening window, so it's 1000mm.

Either way the OP's install is wrong due to the flue length and flues in voids.

 

[CBF]

Rick i am trying to explain why you are quoting the wrong figures, the OP said there are two velux windows, a velux cannot have a flue within 600mm either side or above it but it is 2000mm if it is below, as i said the 1000mm you are talking about is R on the above pic this is not a velux window & therefore the correct distances are as i have just stated.

 

[gunnag]

Well chaps I thought I would post an update.

Since the boiler was broken the GF decided to call british gas to fix it and also purchased emergency cover.

When the british gas engineer arrived he inspected the flue arrangement and the only fault he could find was that there was no inspection panel on the boxed in flue. He said he couldnt do any work until a panel was fitted so I popped down to Toolstation and bought a 30cm sq access panel and fitted it in.

The original problem was that the boiler fan was broken (error F8), I managed to buy a new fan and fit it myself, the boiler now works great.

We are waiting for british gas to come back and re inspect the installation and inspect the flue via the inspection hatch.

When the flue was fitted by the builder, the local council approved the flue location but the builder simply omitted the inspection hatch.

My reading of the regs is that a vertical flue terminal must be 30cm from an adjacent wall and 60cm from a flat roof window (i.e. velux), so I think we are OK in this respect. Looking at the heatline viso plus manual it states the maximum flue length is 8m (minus 1.5m for each additional 90 degree bend) so I think we are OK in this as well.

Thanks for the comments