thescullster wrote:
Hi all

Looking at a replacement central heating/HW boiler and reckon I will need
something like W/Bosch 24Ri. This states a requirement of 2.67cu.m/hr of
gas.

I have a 22mm gas pipe running right across the house to the location of the
current boiler.
Assessment of length and addition of effective length for bends etc gives
23m equivalent length of pipe.
From R D Treloar, this looks to be right on the limit for 22mm dia pipe.

Also we have a gas fire tapped off this main (approx 4 m from gas meter).
This is an occasional use decorative affair claiming 6.5Kw gross heat input
required.

Does anyone know enough to comment on the viability of this install?
What would the effect be if the boiler were running and the fire turned on?

As we have concrete floors throughout and the boiler location is as far from
the meter as geographically possible, what are the alternatives (please
don't suggest moving)?

Also I note that previously it would have been likely that this main would
serve:
Valor Homeflame gas fire
Landing gas heater
Gas cooker
CH boiler 50,000 Btu

Surely this lot would put as much if not more load on the supply?
Final question - if the gas supply pressure as measured is high, can I take
this into account in calculation? I believe 20mBar is the datum pressure on
which these figures are based?


TIA as ever

Phil


the easiest way to see if the installation pipework is to find the
'standing' pressure at the current appliance, then if it is 21 mbar - 1
mbar for pipework, it should be ok, any less then you may need to resize
but as yet, i think, 22mm is the standard maximum pipe size, although i
think it will be moving to 32 or 35 with the advent and realisation of
new technology