Combi boiler with rear flue

[Riley]

Realise it's not to scale but it doesn't look it

 

[SydDenham]

And is that flue 2m below the velux?

Thanks for your comments.

It's not directly below the Velux - it's 350mm offset from the corner of the Velux horizontally and then 600mm down the roof line (to where the flue hits the slate, not the end of the flue which is min. 300mm from slate)

 

[Atouchofgas]

600mm from edges of velux and 2m below

 

[SydDenham]

600mm from edges of velux and 2m below

I guess you are saying that that is the minimum dimensions for the flue positioning?

If so, how does that work? It would suggest that if a flue was 1m below a line drawn horizontally from the bottom of the Velux, then even if it was 10m away it wouldn't comply?

 

[Atouchofgas]

Draw a box 2m below and 600 either side if it's in that box it's a no go

 

[SydDenham]

Draw a box 2m below and 600 either side if it's in that box it's a no go

Thanks for that.

In the Vokera Manual I can see the 600mm measurement if to side of a Velux and the 2000mm measurement if below but no indication of the relevant measurement when the flue is not directly to the side nor directly below. It makes sense however to have a measurement for that scenario - I was relying on Vokera Technical who said,

"Yes, that would be fine. As long as the 300mm clearance to the slate is maintained and it is at least 300mm from the velux window ."

Do you happen to have a source to the diagram you describe please?

I'll draw Vokera Technical's attention to your post to see if they have a comment.

Thanks again.

 

[Atouchofgas]

http://www.gov.scot/resource/buildingstandards/2013domestic/chunks/ch04s21.html

Figure 3.56
Obviously this is Scotland

 

[SydDenham]

3.20 Combustion appliances – removal of products of combustion

Figure 3.56
Obviously this is Scotland

Thanks - nicely evidenced!

Very long shot but I don't suppose English regs are less onerous than Scottish ones?

 

[Atouchofgas]

http://webarchive.nationalarchives....gportal.gov.uk/uploads/br/br_pdf_adj_2010.pdf

Pg 51

 

[Riley]

You should really get a gs engineer in to spec this do you.

 

[woodsy]

Here's a section - excuse the scribbled "computer writing". The flue is just long enough to give a tightest dimension to slate of 300MM

View attachment 26019

cant have the flue protruding by 300mm anyway - unless they've changed it, then no white of flue to be showing.

 

[REDSAW]

cant have the flue protruding by 300mm anyway - unless they've changed it, then no white of flue to be showing.

that cant be accurate!
the flue on the vokera rear extension cannot be cut down less than ''375mm'' i think it is?
that means there will be white showing on non-cavity walls!!

 

[Riley]

Good point chaps. Think it's been decided that the flue can't go where he wants it anyway

 

[woodsy]

that cant be accurate!
the flue on the vokera rear extension cannot be cut down less than ''375mm'' i think it is?
that means there will be white showing on non-cavity walls!!

Being told previously by Vokera tech that the white is not uv rated and will rot over time if in sunlight but may have changed.

 

[REDSAW]

Being told previously by Vokera tech that the white is not uv rated and will rot over time if in sunlight but may have changed.

interesting point. changeable if it lasts 10 years though.lol

 

[lame plumber]

wondered when someone was going to pick up you cant use a horizontal flue to go out through slate roof....

best advice would be to get a fresh set of qualified eyes on the project and mount the boiler somewhere else where it can be serviced and installed properly.