Corgi Regs and location of boiler flue

7 Jul 2005
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United Kingdom
I am hoping that someone can help me out with info on corgi regs. I have had a number of plumbers come to my house to provide quotes for the replacement of a combi boiler and they give ne different versions of the regs. The current boiler is sited in a small space below stairs and very near a small (opening) window. Currently the horizontal flue is 180mm from this window (180mm). What is the corgi reg on how close a flue can be to a window? Must there be 300mm of brick between the flue and the window opening or can we merely bolt the window permanently closed? Must there also be 300mm between the boiler and any internal corners, such as the underneath of a staircase?
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if you make the window permanently unopenable the it can be as close as you like
Don't worry, the regs for your natural draught boiler will be 300mm from the window and 300mm from an internal corner (outside) although there may be some differences with different manufacturers. The replacement boiler will be fan flued and the distances much smaller probably 25mm in each case. By the way a bolted / screwed shut window is still classed as an openable window.
Depends on the boiler manufacturers instructions, they over rule any info in the Corgi manuals. Remember you'll have to put in a steamer to comply with ODPM rules and watch distances to boundries if there is one close by directly opposite the flue.
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You or the plumber will need to check the boiler manual for exact distances from corners etc.

Some manufactures specify different distances from the actual window itself and the actual reveal.

Some plumbers may be happy securing the window others may insist on bricking it up (I'm of the latter)

As for the understairs location there are regulations concerning this location and fireproofing depending on the number of floor levels above.
My local inspector doesn't aprove of screwing windows shut "someone could convert it back to openable".

Quite likely you fall fowl of distance from boundary rules and naf location for the service engineer later.

Get it put on a pedestal in the centre of the lounge with floodlights and a vertical flu through centre of house to roof, and put an image of two jaggs on the wall to bow down to every 4 hours.
Corgiman, dont quote that to your CORGI inspectors!

For the last couple of years it has had to be 300 mm from the brick opening!

Some of the armchair experts may quote the chapter and verse.

The "logic" is that Anglian will come along and replace the screwed up old window with a nice UPVC double glazed replacement with an opening light!

Tony ( Glazier )
I have quoted THAT to my CORGI inspectors tony

I have also SHOWN that to my CORGI inspectors!!

I did not say screw down the window I said Make the Window permanently unopenable

which I have done with a drill, a screw or two, some filler and a hacksaw blade. so as the screws are not accesable by the home owner

it just says openable window in the regs, it doesnt say a screwed down window doesnt constitute a permanently closed window.

In some cases you can remove the openable window and repace it with one that dont, in the case of PVC this may be the only option, but it still can work out cheaper than moving the boiler from the desired location.

on the point you made about anglian coming back and reopening a window, well we cannot be held responsible for what other people do after we have left

I have installed many open flued boilers in my time to find a conservatory whacked on the back of the house right over the lovely air vent I installed.

We can only insure that the installation conforms to GSI&UR while we are there, or are you saying that we must return periodically to ensure the home owner has cocked up our lovely work?

I have edit this a few times as I dont want to get anything wrong and anger agile :)

If you can show me that I am wrong agile I will of course change my working proceedure, but I have been through this question many times with many installers, building inspectors and CORGI inspectors so am quite happy that I am right and am not contravening the regs in anyway.

by the way please dont think that I am being atagonistic with my post, I have great respect for your knowledge and would appreciate any crictism you have.
Some cowboy had put the boiler flue under the lintle next to the kitchen window.

To pass boiler on a CP12 I took out the sealed unit and used clutch head security screws to secure the casement.

I locked the window handle - jammed a screw in the lock, wrote "DOES NOT OPEN" in red pen and told the landlord.

Went back the following year and found the window could now be opened and the glazing bars butched - new tenants had moved in 6 months before and the landlords dumb ars**d contractor had spent a day re-opening it.

Brick it up if at all possible.
Can't prove a secured shut window is not openable but I do remember a company brief around 18 months ago where we were informed that an openable window which had been fixed shut was still classed as openable wheather physically possible or not.
Mand, please note, there is no such thing as Corgi regulations, Corgi do not make any regulations, the gas regulations are made by the HSE
ollski said:
Can't prove a secured shut window is not openable but I do remember a company brief around 18 months ago where we were informed that an openable window which had been fixed shut was still classed as openable wheather physically possible or not.

As far as i am aware that is the correct interptretation.

Agile wrote:

For the last couple of years it has had to be 300 mm from the brick opening

I thought that it was 150mm.
Baxi along with others say minimum 150mm to opening in fabric in of building which is to accomodate a built in element such as a window frame as per BS540. But i would imagine they are wrong an agile is right
doesnt manufacturers Instructions superceed the BR in a case like this?

not that it matters to the OP but I always thought they did
wb also stipulate 150mm from an opening in the fabric of the building eg door or window opening

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