must i replace the gas pipe?

[Reg Man]

Standing pressure at the boiler tells you nothing of importance. Its working pressure on the boiler inlet, under maximum flow with all appliances running which tells you the correct figure.

 

[Masood]

Fit one of these close to the boiler. That will give you your working pressure without the restriction from the boiler's gas valve. As already said, make sure other appliances are on full blast. No cheating by "forgetting" to turn them on!

GAS PRESSURE TEST EQUIPMENT