Ed Sirett coughed up some electrons that declared:

Forget Part J, if you follow the gas appliance makers instructions (which
may or may not supercede BS 5440) then you will be Part J compliant. Part
J are more general regulations on heat producing appliances - including
ones that really could set the house on fire!

IIRC BS5440-1 permits GAS flues between 300 and 2000mm above the ground
level of a walkway if there is a terminal guard. If Veissman wish to up
the rule to not allowing any flue below 2.1m above a walkway they have
every right to do so. However this may be a drawback commercially as it
will be a discouragement to choose this make in certain locations.

Thanks Ed. It is weird as they appear to have only applied it to this one
model (not that I've read all the manuals but I did look at some others).

Think I'll give them a ring and see why they've stated that. They might have
meant a public walkway rather than a garden path - it's not at all clear on
their diagram.

Sounds like you need to make the area unpaved?


That is of course the fallback. I can route the path further away from the
house at that point so it's not really a problem - well, not enough of a
problem to not use an otherwise ideal siting for the boiler.

Cheers

Tim