Ideal Logic combi 35, Flue question

29 Apr 2013
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United Kingdom
WE have an Ideal Logic Combi 35 fitted 6 months ago under the 'nest' scheme and so far very happy with it.
When the fitters were here they left us a high level flue extension kit (inc' the flat roof collar ),as we explained that the current 'external wall' the boiler is hung is soon to become an internal wall, as per the approved building reg plans we showed them at the time.
My question is, whilst the instructions clearly show a minimum distance between the air inlet and flue terminal there is no max length the exhaust flue can be.
I have 3, 1m lengths, using either a 2m flue or 3m both comply with the minimum siting dimensions for fanned
flue terminals.
Is there a maximum distance between the air intake & flue outlet?
All the work on the flue will be done by a gas fitter when they install new gas pipes. I ned to know the answer to tell if the builders are telling porkies
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If no-ones answered yet it probably means no-one knows for sure. Best bet is to phone ideal tech and they'll tell you.
I rang the number supplied with the extension kit and the guy there simply stated that whilst the minimum distances were set the actual max length wasn't stated. It seems it's down to the fitter bearing in mind the recommended distances to openings etc.
Thanks anyway
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There is a graph in the link that posted up as far as I can see, max pluming kit length is relative to the horizontal flue length .

May be its me but i am a bit confused

are u saying the wall that the flue exits on is now going to be an internal wall

where will the boiler draw its combustion air from ?
The wall will be in a covered courtyard, open at one end. In the first set of plans the boiler was to be mounted on a disused chimney breast, the exhaust flue running up and the 'intake' drawn from the interior of the chimney.
Those plans were approved but we had the architect change them due to cost considerations.
There was some discussion regarding the siting of the boiler and I've been assured by British gas there's no problem, the horizontal flue length is approx 400mm, on one of the flue extension kits left by the fitters someone has written 'max flue 7.5m', however I have no idea if that's correct.
Read the graph in your link plume length is dependent on the flue length !!

and as a matter of interest the ideal Logic may well turn out to be a turkey , like the in-famous isar , icos , & response that the same company dumped on the market.

Warranty probably will not amount to a bag of beans. there will be trouble ahead (may be ?)


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