Boiler flue issues

[sandleic]

Hi New poster so go easy (please!),

Recently moved house and looking to replace old boiler with a combi so as to free up space in small bathroom (remove hot water tank, airing cupboard etc).

Would like to have the boiler wall hung in the utility room (where the current floorstanding one is - it's flued up the chimney breast). Problem is the flue positioning for new combi as the only external wall has a window and door with only a small (8 inch) gap above through which to take the flue - on the outside wall this would exit just at the very top of the arch above the window. Had 3 fitters come round - 1 said doable but v. tight, other said ok (but didn't really measure), one said no (but didn't really measure up).

I've done a bit of reading the last few days and have two questions:

1. Can you use a 45 degree exit to go at the top of the boiler? This might be necessary to leave the necessary clearance at the top - otherwise the top of the flue may be flush with the ceiling.

2. The flue would be exiting fairly close to the window (corner top of arch). The window probably opened once but from the outside it's been painted shut over the years. We wouldn't want to open it and two of the fitter suggested we'd have to nail or screw it shut. Is this enough or would we have to take more permanent measures to get it classified as non-opening.

Any help appreciated.

Cheers

San

 

[namsag]

If a plume kit is used some manufacturers will allow the flue to exit within 4 inches of the window as long as the exhaust exit of kit meets regs regards clearances from windows etc

 

[sandleic]

Thanks for the reply.

Sorry I should have also said that the flue would exit in between the soil vent pipe and the bathroom plumbing from upstairs (bathroom is directly above utility) so any flue plume kit couldn't go directly against the outside wall. It would have to jut out to clear the exisiting pipes and apart from being an eyesore I'm not sure if this is allowed?

San

 

[vulcancontinental]

Thanks for the reply.

Sorry I should have also said that the flue would exit in between the soil vent pipe and the bathroom plumbing from upstairs (bathroom is directly above utility) so any flue plume kit couldn't go directly against the outside wall. It would have to jut out to clear the exisiting pipes and apart from being an eyesore I'm not sure if this is allowed?

San

Ideal's plume kit permits the flue terminating within 25mm on one side of the air duct to a soil or RWP.

Vokera's also permits 25mm from a RWP or soil and what might be helpful is that the vertical plume kit flue is proud of the wall and usually uses an offset to bring it closer to the wall. If you didn't use the offset bends then you might get the clearance you need (I can take a picture if this helps as I have one on display, I work for them).

 

[bengasman]

You can not stick a flue trough an 8-inch height of wall above a door/window.

 

[Agile]

Ben means because the supporting lintel or beam occupies that height above the window!

All of these questions sould be better asked of the selected installer although you must make it clear that you expect them to do it totally within the regulations as enforced by Gas Safe and to take responsibility for any correctione which may be needed to make it comply.
That wil sort out the men from the cowboys!

Tony

 

[bengasman]

Indeed.

 

[sandleic]

Thanks for your advice - guess I'll have to pin the fitters down. I'm guessing the lintel would be above the window arch?

Would it be possible to take the flue the following way (directions given standing in front of boiler):

exit vertical up, 90 degree right and along internal wall, 90 degree going back through the wall which is between the utility rm and kitchen, along wall in kitchen (above fitted cupboards) and then 90 degree right out to external wall?

San

 

[bengasman]

It's impossible to answer this kind of question from behind a keyboard.
The simple answer is: find a good RGI, and let him do his job.

 

[expertgasman]

It's impossible to answer this kind of question from behind a keyboard.
The simple answer is: find a good RGI, and let him do his job.

Spot on. And remember 1 of 90 degreee bend equals 1M of allowable extension