Gas pressure question

[Wormwood]

Do not attempt anything on your gas supply contact a GSR he will diagnose your problem and if you should need a vist from cadent he will arrange another vist . cheers kop

See post 16 paragraph 3

I've worked on a gas rig in the North Sea so I'm not tempted to do anything myself gas-wise.

 

[Wormwood]

I still don't see why the pipe has to be 22mm as long as the pressure drop is within regs (as per Shaun and Snowhead's advice).

 

[ShaunCorbs]

I still don't see why the pipe has to be 22mm as long as the pressure drop is within regs (as per Shaun and Snowhead's advice).

The only time is if it's out of spec e.g. More than allowed pressure drop

 

[GH77]

If the old boiler has a pilot light then it will be an atmospheric burner, it will only require enough gas pressure to make Burner pressure, for example 10mb, your new boiler will be a zero governer, these ideally require 20mb inlet working, but depending on the boiler can be as low as 14mb, more usual is 16.5 to 18mb. If your meter regulator is supplying 19-21mb working pressure and you then don't have enough working pressure at the boiler, then your Pipework is undersized. The engineer who carried out the survey should have carried out a pipe sizing exercise to determine if the existing pipe is suitable, he has said it is not and requires upgrading for a new boiler, if he hadn't done this and just fitted a new boiler, he would be liable to correct the installation error at his own cost. Sounds like he is a professional doing a good job, I would suggest you follow his advice

 

[king of pipes]

Providing the pressure drop is within the regulations then you are ok , if not then it will need to be addressed i am afraid ,when you upgrade any proffesional Gsr would upgrade a 30year old gas supply when fitting a new modern condensing boiler any debris rust or otherwise would not be a issue then and you will have a supply correctly sized and which will last the life of the boiler and longer regards kop

 

[Wormwood]

The only time is if it's out of spec e.g. More than allowed pressure drop

Ok, thanks Shaun - I understand. What do you think of my plan in post 17?

The engineer who carried out the survey should have carried out a pipe sizing exercise to determine if the existing pipe is suitable, he has said it is not and requires upgrading ................. I would suggest you follow his advice

Thanks for that explanation GH77.

The pipe coming out of the meter is 22mm, so it reduces to 15mm somewhere inside the house. It would be really good if I could find out exactly where - maybe it's right next to the boiler (the 15mm disappears into the plaster so I can't tell).

Btw, there's a rust-coloured deposit all over the inlet pipe to the meter. I wonder if it's got inside the pipe as well. Hmm.

Providing the pressure drop is within the regulations then you are ok , if not then it will need to be addressed .....

Ok, thanks Kop.

 

[ShaunCorbs]

I would get no 2 done first and see what you get

 

[Old Account]

Yes we're only allowed max 1.5 mbar drop from the meter to the appliance working

I think rules have changed 1mbar drop max. From meter to appliance 1mbar drop only!

 

[ShaunCorbs]

I think rules have changed 1mbar drop max. From meter to appliance 1mbar drop only!

Still 1.5mbar max

 

[GH77]

Depends where your pressure test point at the boiler is, whether you've got one before the boiler or using the test point on the Gas Valve, picture paints a thousand words