On 03/03/2021 12:16, Robin wrote:
On 03/03/2021 11:22, bert wrote:
In article , Robin
writes
On 02/03/2021 23:57, Fredxx wrote:

snip
Â*If you know the kW of your boiler you would be able to calculate
the size of pipe you actually need. In domestic situations with
limited pipeÂ* runs 22mm copper pipe is a safe bet, plus to save
embarrassment to GasÂ* Safe installer Gas Safe have made a blanket
requirement to combis whereÂ* they must be piped in 22mm. Though I
would be happy to have the lastÂ* sectionin 15mm.


I don't want to give false hope to the OP who may well need a new gas
pipe.

But I've seen before on some sites that "Gas Safe regulations now
state that gas supply pipes from the meter to a combi boiler must be
at least 22mm". Smelt to me like a way to get more work and avoid the
bother of calculating pressure drops.Â* Gas Safe have no power to make
regulations.Â* And while the Gas Safety (Installation and Use)
Regulations were amended in 2018 I can't see anything in them about a
minimum pipe size. Have I missed something?


Only that when combi boilers first appeared a lot of installers used
the existing 15mm which was then found to be inadequate.

Thanks but I was aware of that.Â* And it's a bit of a leap from that to
"you *must* use 22mm even if it's a run of 1.5m with one bend to a 24 kW
combi". Only makes sense to me if Gas Safe members can no longer be
trusted to do sums and measure pressure drops at existing boiler.

Again, simple rules for simple people. I had huge arguments with the
building inspector when I wanted to use single glazing. But a report by
a heating engineering consultancy revealed that with enough insulation
in the walls and floor it met the regulations, was, in the end enough.

heating engineers of te corgi flavour doi not come equipped with brains
sufficient to deal with complex rulesets. 'use 22mm' is as simple rule
even a CORGI man can understand....

--
"When a true genius appears in the world, you may know him by this sign,
that the dunces are all in confederacy against him."

Jonathan Swift.