boiler exhaust fumes through party wall

[SimonH2]

I'm not a gas fitter, but I really don't understand the regulations being quoted in this context. So comfirm, a flue cannot be run less than 300mm from a boundary when run parallel?

AUIU, correct.

I know people with gas boilers mounted directly on boundary walls in kitchens etc with flues exiting out the top . Given the boundary as at the middle of the dividing wall this flue will not be 300mm from it.

Yes, it's not to standard and strictly speaking shouldn't have been done that way. I suspect that in pretty well all cases it would have been possible to bring the flue away from the wall by using a 45˚ or 90˚ bend at the boiler end (ie boiler flue turns horizontally, but pointing 45˚ or 90˚ away from the mounting surface, the bend then turns this parallel to the wall but further from it) - though I suspect few householders would consider this acceptable.

As I understand it, the OP has a pipe running along his neighbour's side of the party wall, then exiting near the boundary (we haven't been told how far) but 2m from his patio doors, and 1 ft above the top of them. Are these distances not far enough for a 50kW boiler (which I know is a fairly hefty size). If not how far should it be?

From memory of the regs, this would be sufficient if it were his own flue and openings. But, the installer must also take account of external influences.

I'd have thought that the upstairs would get more effect from the plume, given the above information and the management kit applied.

It can be tricky. It sounds like this is a bit of an enclosed space - and airflow can be complicated.
If the absence of significant wind, yes the plume would flow away from the terminal and upwards. Once you introduce wind, and a complicated building shape, then eddies can carry the plume down, sideways, any which way. I suspect the problem is possibly slightly worse these days due to the lower flue temperature ina condensing boiler - the old boilers had a hotter flue with more water in it which would have been more buoyant.

 

[Dan Robinson]

A picture is needed really. I suspect that the whole thread is a bit of a fishing expedition.