"Larger installers"?? The size of the installing company is irrelevant, the same applies to any installer. They send emails cofirming to anyone who asks.
However, WB's strictly unnecessary stipulation is driven by their wish to have their boilers working properly. So many installers hardly give a thought to the supply size, especially where there was already a boiler working in the same place.
It's hardly surprising. The "1mbar" requirement is pretty arbitrary, and not something a manufacturer cares about. The gas sizing tables are as we all know, wildly inaccurate.
IF you have sufficient pressure throughout the gas supply when everything's on to keep everyone happy, the pipe size doesn't matter.
The pipework should be cleaned of flux residues, and pipes shouldn't touch.
Ok it looks averagely (as Tony says) untidy, partly because of the old pipework. Apart from that, I think some plumbers are ridiculoiusly prissy about supposed "standards" of no value, which they imagine are important.
The pipes (arguably) don''t need clipping, they're fixed to the frame of the boiler.
It looks like the gate valve was inherited from the previous installation. If it's closed, it's OK, as long as WB say so, whcih they do.
A sloping pipe here or there looks untidy, but makes no difference to the performance. A few elbows more or less in the water pipes make no difference at all. Somewhere like this, bends wouldn't be any better.
He's got full flow flush points, he's powerflushed it we're told, he's got his Bonding done, he's WAY ahead of many who do a cosmetically pretty job missing out what really matters!
Well that's my rant for the day
