15 or 22mm gas pipe to boiler?

[Bloggsyboy]

We have a Potterton combi 80 boiler installed many years ago with a 15mm gas supply pipe. A plumber said we should have a 22mm supply pipe and checked our pressure which is 18 when it should be 20. This would be a big job so I thought I'd see if other people agree. The only problem we have to make me think of doing the work is that the shower goes cold if anyone in the house turns on another tap.

 

[mrgas]

18mb is good enough for your boiler.
Altering the pie size wont make a differance to your hot water.
The boiler can only produce a certain amount of hot water. Not enough to feed 2 taps at once. The hot water will go to the tap with least resistance. Your shower looses out.

 

[Bloggsyboy]

Thanks Mr Gas

 

[namsag]

Although 18 is good enough to run most boilers it does not meet the regs if you have 20mb at meter there is only a 1mbar drop allowed between the meter and appliance.
So anyone telling you it needs upsizing is telling you the truth

 

[Bloggsyboy]

Good tip, thanks, sounds like we are loosing too much pressure between the meter and the boiler.

 

[Agile]

Its not a tip!

Its the plain fact that your installation does not meet the current regulations.

But upgrading the gas pipe will not alter the performance of the boiler.

It will be needed when the boiler is replaced ( and that should be fairly soon as yours is getting rather old ).

Tony