Andy Hall wrote:

You are going to have to do something about the gas supply anyway. the
issue is the gas rate required by the combi - it is not an issue of
condensing or not. Perhaps it is possible to do this with running a
new pipe other than through the floor?

One commonly used solution these days is to run the gas pipe round the
*outside* of the house, and just come back in near the boiler.

I believe both options will require a vertical extended flue over 2m,
as distance of the existing/new horizontal flue terminal to
neighbouring boundary is/would be 2.5m.

I think you can have less than 2.5m if required.

He is looking at the safety requirement which is 0.6m. The other is
only to avoid potential nuisance to the neighbour from a possible
plume. With a very long flue, it is quite likely that there would
not be significant pluming anyway because much of the water vapour
would condense and run back to the boiler.

The longest "throw" of visble steam from the flue on my boiler
(installed on the side of the house - pointing at the neighbours
property some 2.2m away), is at most 400mm. So it does not even get as
far as the boundary.


--
Cheers,

John.

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