Domestic gas boiler supply pipe regulations?

Question

Domestic gas boiler supply pipe regulations?

Answer 1

The installation instructions will tell you pipe size and pressure specs.  If you don't have one because the boiler is old, you may find it is not legal to install it as it does not meet the current efficiency.

generally most domestic boilers will be fine on 22 to within a metre of the boiler if the inlet is 15mm.  If you use 15 all the way, it may not perform to specs when on full load.

Answer 2

There are many regulations regarding size,type of material, fittings,locations etc.Your question needs more detail.