Gas being re run threw my house.

[anne36]

Hello everybody,

I was wondering if you could all help in clearing something up for me please.

The gas people have all been renewing the mains up at my Grandmas house, they have done this and spotted a leak inside and capped it off. They said this was common when the majority of pipework is still in lead.

I have had two people out on my grandmas behalf for quotes that were similar in price but different in ideas. I will explain what gas appliances we have , 2 gas fires, 2 wall heaters, 1 oven, 1 hob.

I have been advised that it will be 25 - 30 metres of pipework to connect to all of these appliances from the meter.

The first engineer advised that he would run from the meter in 22mm upstairs under the floor, and then come off in 15mm to the wall heaters, downstairs to gas fires, and also hob and oven.

The second engineer advised it would need 2 22mm pipes run from meter to half of the appliances each.

By the two different responses i am confused as to who is right.

Please can someone advise as to which is the right way, or are both ok.

As you all can appreciate i no nothing about this and want it done right for my grandma.

thanks

 

[swidders]

I'm no expert in this, but I am aware of the need for installers to do calculations regarding pipe sizes given distances, flow rates, pressure losses, number of bends, appliances etc. If they are experienced enough to do it by eye and subsequently sign it off, then you must take their word for it.

The one who prefers to use 22mm may well be making allowances for future expansion to the system, more that the 15mm bloke. Question them both about their decision, quoting the other. This may clarify.

 

[LeedsPlumber]

Its hard to say wich is correct without seeing and knowing appliance outputs, however as long as each appliance has the correct supply of gas then either way will do. For me i would not want pipework running down the corner of a room if i didn't have to so would probably split at the meter. But thats me.

 

[davebgas]

Gas pipe sizing is based on a calculation ensuring that the maximum pressure loss across the system is no more than 1mb.
Depending on the route the installer intends to take versus the KW rating of the appliance, distance, number of bends in the pipework etc will dictate as to what size pipework will be required.
Some installers quite rightly I think 'oversize' pipework to the boiler to cater for future improvements, whereas, and again quite rightly some will quote using the smallest pipe, thus, smaller cost to adequately supply the appliance.
Both ways are perfectly acceptable so long as the maximum pressure loss across the system is as mentioned, not more than 1mb.

Hope this helps

Dave T
Incorporated Engineer, Member of the Institution of Gas Engineers and Managers.

 

[anne36]

Thanks very much for your replys.

My grandma has two gas wall heaters upstairs. Two gas fires downstairs, hob and oven.

I have spoke to a retired plumber who says he has been out of it for too long and regulations change.

Is it possible for one 22mm pipe to supply all these appliances if it is in 22mm to all of upstairs and then be dropped seperately in 15mm to gas fires , and seperate again to hob and oven?

thanks again everyone.

 

[LeedsPlumber]

Yes it is possible to run one 22mm pipe and tee off to each appliance in 15mm assuming all calculations are correct and 22mm pipe will be large enough. Without know the output of each appliance it is impossible to say.

 

[swidders]

So, assuming that both will be installed correctly, you have a dilemma.

Either

1/. you have less disruption to flooring and furniture and mess and have pipes running down walls from upstairs, or

2/. you have both upstairs and downstairs disrupted but have a neater finish to the pipework.

This noone can advise on - although a couple of days way somewhere while the carpets and floor is up, coming back to a clean and tidy house, would be something that i'm sure she would appreciate and decrease the forthcoming potential stress!!!

 

[anne36]

I was told it all needing running upstairs and then be dropped due to solid floors as it would create a lot of work if pipe was to run in to them.

Pipes that dropping will be cased in.

 

[anne36]

One question the retired plumber said was worth a mention.

Does it make a difference whether the 22mm branches off in to two at the meter or in the room above?

Thanks for all your help.

 

[anne36]

Also should we try and get plumber to sink the pipes in to the walls where they will come down?

thanks again everyone, your all really helpfull.