On Mon, 22 Dec 2008 00:18:43 +0000, Tim S wrote:

Ed Sirett coughed up some electrons that declared:


Modern boilers not only don't need air for the combustion (as it comes
from outside) but also they don't need any for appliance cooling.


Hi Ed,

If you're still around...

I've come across some conflicting information on flues (this case,
balanced, gas).

The Viessmann 100 Compact installation manual shows a flue lower than
2.1m above ground and *next to a "walkway"* as being unacceptable.

However, Part J makes no mention of any distances from "walkways" and
neither do any other Viessmann documents.

I'm aware a flue must be guarded if people are likely to make contact
with it.

Is this a new thing, or have Viessmann made an error?

The horizontal flue will be coming out of a wall on the back of a little
annex on the back of the house. The roof is low and flat and the eves
are about 2.1m above ground. Flue needs to go lower than 2.1m to both
meet the 200mm clearance below eaves rule and Viessmann's requirement
that there be 300mm clearance above the boiler casing.

Technically, there's a path (private, in the garden) going by there,
although this could be tweaked.

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.

Sounds like you need to make the area unpaved?




--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html