Toby wrote:
Folks,

In the process of installing a new boiler, but am not really sure how
I should calculate the gas pipe size to the boiler.

The gas meter is just under 5 meters away (as the pipes will run) and
this will be the only gas appliance in the house (the Kitchen is the
opposite direction to the boiler too, so if any gas is needed or
there, it won't need to branch off of the run the the boiler)

Can someone possibly help me understand how to calculate this!?

(There will need to be two bends in the pipe, I assume swept bends
are going to be preferable here?)

Many thanks!

I'm no expert in these matters but we have a similar setup in our house and
we have 18mm up to about 1m away from the boiler where it reduces to 15mm.