Best flue position

[Malc]

I'm considering an extension and at same time fitting gas central heating (not me fitting the gas of course). Everything is variable including boiler position and flue.

Is it better to have the flue exiting from the roof? Or is a wall exit just as good for the risk of nuisance? I could have longer horizontal flue inside (does that help remove condensate?). Or I could go vertical but that would be from ground floor (probably) so access panels and inspection is then a pain. Or I could go through downstairs wall then have a bit of vertical flue management pipe, or I guess a bit of vertical flue. It's on a don't care about side of the house when the bins are stored. It's a 2m wide access way that faces next door (and next door's flue).

TIA

 

[Agile]

So if you are not going to fit the boiler yourself then don't you think these questions are best answered by your gas registered installer?

Tony

 

[Malc]

Well his would be one opinion and it is current Easter weekend. I'm looking for a range of opinions and the whys and why nots.

 

[45yearsagasman]

All things being equal, and regs conformed to regarding clearances, I would always go for through the wall flue, keeping the length as short as possible, and reducing extra costs associated with verticals or extended flue runs.

 

[ianmcd]

As Pete Correctly advised vertical flues can become expensive and mean breaking into the fabric of the roof, consider that if your new boiler lasted ten years and you need a new one, then you will need scaffolding and a roofer and whatever health and safety can think of to replace a vertical flue, a concentric will be easily replaced, as far as performance goes comparing concentric to horizontal I can only say that any vertical flued appliances I have worked on seem to suffer a bit more from excessive condensate but that is purely a personall opinion

 

[Malc]

OK, That's an interesting point. So boiler replacement would mean replacing the flue as well. The roof is quite tall (if I could site the flue there). I suppose it might be possible to replace the flue up to the vent tile but otherwise that does get tricky I can see. I suppose 1st floor through the wall is just a ladder for access.

 

[ianmcd]

Yes if you replace a boiler you have to replace the flue also, if you go for the same manufacturer then sometimes you can keep the same flue but not always and who knows what our lovely HSE will rule in the future