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

 

[Chalked]

I think this thread should be closed.
There is too much gas related info being given to a diy'er who should just employ a good gsr to install the new boiler and update the supply pipework as needed.

 

[GH77]

He already has, just reassuring him that his GSR is correct, why he's correct and that he's not being ripped off

 

[townfanjon]

He already has, just reassuring him that his GSR is correct, why he's correct and that he's not being ripped off

Agree with chalked , this should have been closed yesterday

 

[Wormwood]

I think this thread should be closed.
There is too much gas related info being given to a diy'er who should just employ a good gsr to install the new boiler and update the supply pipework as needed.

I am NOT a DIYer!!

I've already said several times that I have no intention of doing it myself and that I have and will use a qualified gas installer.

Read posts 16 & 21!

Is that clear enough for you?

I will not say it again.

 

[Wormwood]

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

Yes, I think you're right. Then no 1 if it's still too low. (My meter really is ancient, spiders crawling out of it, etc, etc).

Btw, I reckon the 22mm-15mm reducer is closer to the boiler than I thought (I had a closer look last night). The 22mm comes out of the meter and goes straight back through the wall horizontally. After 10 inches, it disappears behind the plasterwork inside the lounge.

Here it must either a) turn vertical until it reaches 1st floor joist level - or b) go off in another direction.

Assuming a) is correct, it must turn horizontal again and run through the joists, over the hall, over the downstairs toilet, and into the kitchen, where the boiler is. Then it turns vertical again (so it's now pointing downwards), reduces to 15mm and runs down inside the plaster to the boiler.

All I have to do is find the point where the reducer is - my guess is directly above the boiler at 1st floor joist level.

 

[townfanjon]

Mr Wormwood , you are out of order disagreeing with my thread closed statement , you are clearly "picking everybodys brains" on here , I saw this thread develop and thats why I left it alone . Leave the gas alone !!!!!!

 

[Wormwood]

Mr Wormwood , you are out of order disagreeing with my thread closed statement , you are clearly "picking everybodys brains" on here , I saw this thread develop and thats why I left it alone . Leave the gas alone !!!!!!

What's the point of the forum if people can't come here and ask for advice!

The reason I disagreed with your post 33 is that it agreed with Chalked, who said in post 31 that I should use a GSR. I have already stated countless times that I will not touch the gas myself and will use a GSR!!!

I am trying to establish whether there is an alternative to running 20 feet of 22mm pipe on the outside of the house, across two doors, one window and through one gate. This was the only solution offered by the installer mentioned in post 13.

He was wrong. The solution is to find the 22-15 reducer, which I now know is on the inside of the house. I also know, thanks to the helpful people here (Shaun, Snowhead, GH77 & kop, etc), that I could stick with 15mm if the pressure drop does not exceed regs, or contradict the new boiler's pipe spec.

 

[masons]

He was wrong. The solution is to find the 22-15 reducer, which I now know is on the inside of the house. I also know, thanks to the helpful people here (Shaun, Snowhead, GH77 & kop, etc), that I could stick with 15mm if the pressure drop does not exceed regs, or contradict the new boiler's pipe spec.

really !

 

[jtsplumbing]

Question you say that you have a glow worm Balanced Flue boiler, is this a standard boiler with hot water tank ? and is it being replaced (Upgraded to a combi) ? or are you just having a boiler swap ?

 

[Wormwood]

Question you say that you have a glow worm Balanced Flue boiler, is this a standard boiler with hot water tank ? and is it being replaced (Upgraded to a combi) ? or are you just having a boiler swap ?

Yes, I've got a bog-standard Glow-worm Fuelsaver MkII with HW cylinder & immersion heater in airing cupboard and a small F&E tank in the loft. New boiler will be a straight swap - it won't be a combi (partly because the cylinder, pump, motorised valve & tankstat etc have already been changed for new ones).