Gas supply issues for Combi Boiler

h13odg

I desperately need some help and advice.

My combi boiler has recently packed up and I need to replace it. I have decided to have a Worcester Greenstar 37CDi fitted.

Before I do I have a problem with my gas supply. My gas meter is 53m from my house, connected by a 28mm pipe. I have been advised that the current 28mm pipe will not deliver the required working pressure for a modern combi boiler because of the pressure drop over such a long pipe length. Apparently the maximum pipe length for a 28mm pipe to deliver the right working pressure is 40m.

I have been advised that the only solution certain to resolve the problem is to move the meter closer to the house. It has been suggested to me that leaving the meter where it is and replacing the current 28mm pipe with a thicker one might work but nobody seems to be sure.

I have contacted Northern Gas Networks and sent them a diagram. In their response they have indicated that not only will they need to replace the 53m of pipe on my property but also the 6m of pipe under a public highway from the gas main under the road to my property's boundary (where the meter is currently cited). They are proposing to fit a 63mm PE LP service for the total 59m length.

The problem I have is the cost. They have provided me with 2 options: 1) £5800 for them to do everything, and 2) £3500 for them to replace the 6m of pipe under the public highway and fit the 53m pipe where I have organised the excavation of an open trench or appropriate duct.

Where I need the advice is as follows. I don't have a problem paying to upgrade the 53m of pipe on my land. However, I don't see why I should have to pay for the upgrading of the 6m of pipe under the public highway, which accounts for £3500 of the total cost. To me if the pipe under the public highway is the limiting factor in delivering the required working pressure for a modern combi boiler then surely the supply directly from the gas main is not fit for purpose, so I don't see why I should pay for this upgrade.

Am I missing something? I would welcome any advice. If anybody knows anybody I can speak to about this I would be very grateful.

Thanks

Pincher

The instant hot water is the heavy gas user. If you go for a heat only boiler with a hot water cylinder, the existing gas pressure is probably OK.

Put in an infrastructure upgrade request.
Hopefully they will get round to it in the next ten years,
at which point you upgrade to a combi.

HappyMJ

Forget about combi and just install a heat only boiler. There is no way you will recover the costs by using a combi over a heat only boiler.

macman

Do you actually need to go as high as 37kw? That will probably be twice what is needed to run the CH side (how large is the property?) so I presume you are looking for a very high flow rate on the DHW side for some reason?
If you went down to a lower rating, would the upgrade still be required?
And is your water pressure and flow rate adequate too?

gas4you

Why has nobody suggested to you that they work out the pipe sizing using 35mm copper?

You may find this is all you need.

All domestic RGI's can now work on 35mm pipe work, but they will also have to calculate the pipe volume as well as the pressure loss.