Bigger meter and bigger pipes required - can SGN force me to do this?!

Largergaspipe45

We are having a second boiler put in to our house. The plumber ran the gas peak fllow rates and caculated existing at 68kw (see breakdown below)

oven = 15kw

boiler = 35 kw

Pool boiler - 18kw

I have been told that a standard gas meter is set fir 65kw capacity but the gas networks assume a max use of peak flow at 80%. The additional boiler woiuld be 35kw taking us to 103kw. The plumber had told me that I would need a bigger meter so I applied with Octopus (my energy providner) and they requested me to fill out a GT that asked for the SPEV rating (the new intended peak flow of gas).

Southern Gas Network sent out a surveyor who said that a bigger pipe would be required. Plumber said he had never come across this before and that pipework was usually of sufficent size.

SGN have quoted £10k to "do the trenching" on an incredibly basic scale map ignoring the fact that their proposed route goes directly through a 12 inch thick 200 year old stone wall and across an electric gate trench and two corten steel edged flower beds and a set of brick slips. When I questioned this and asked why they wouldn't mole it they said they would "have a look when they started work".

I also understand that one is never actually using anywhere near max peak flow at any one point because the boilers are trickle boilers and you wouldn't have all 5 gas rings on at the same time.

Final thing to note - the house was split into 2 halves in the 70s, when we came we had a separate supply put in but this was in 2013 and SGN are claiming they only have records going back for 7 years (I have asked them to access what is surely recorded work when it involved a mains gas supply) but that only a 20mm pipe comes in to the meter and that they would "investigate further" when they start the work (this is the smallest possible gas pipe, not even 32mm which begs the question why, for a large house, they didn't increase pipe size in 2013)

Basically my questions/issues are:

1. I have tried to find other registered bodies who can quote for this and I went to the LRQA to find a GIRS accredited UIP but no success.
2. Do I have to have the new larger diameter service pipe installed at all or could I challenge this in any way?
3. How can SGN send out a surveyor and give such an appallingly basic quote and poor service all round just because they are a national service?

I am a complete lay person in this field and just relied on what my plumber had told me (he said he has contacted lots of colleagues/other plumbers and none of them have come across this before). So I was certainly not expecting to be charged an additional £10,000 for the project and be hekd to ransome for it.

I would be SO grateful to anyone with knowledge of gas network providers and this sort of upgrade who has any ideas or pointers at all as I am at a bit of a loss now.

THANK YOU SO MUCH IN ADVANCE FOR ANY HELP

QrizB

Welcome to the forum! This thread would be better on the main "Energy" board; I'll ask for it to be moved.

SGN have quoted £10k to "do the trenching" on an incredibly basic scale map ignoring the fact that their proposed route goes directly through a 12 inch thick 200 year old stone wall and across an electric gate trench and two corten steel edged flower beds and a set of brick slips.

Are you arguing that £10k is too little for the trench they've proposed, or too much? I can't quite tell.

I also understand that one is never actually using anywhere near max peak flow at any one point because the boilers are trickle boilers and you wouldn't have all 5 gas rings on at the same time.

The thing is, though, you've requested a 103kW supply and that's what SGN have quoted for. The basic domestic gas meter is a U6 size, which is good for 6 cubic metres of gas an hour - about 65kW. You can supply a U2 meter through a 22mm pipe quite happily.

I think the next size up is U16, which can cope with 16 cubic metres an hour (about 170kW). That's going to need a bigger supply pipe.

Rodders53

Change to electric cooker (induction hobs are excellent) = 15kW saved. No need for bigger gas pipe. Or convert and run it on LPG (bottles) - expensive cf mains gas but £10k buys quite a lot of gas bottle refills.

Pool boiler: change to AS heat pump? Possibly ditto for the main boiler and then ditch mains gas altogether.

Mind, you'll then complain about the cost of installing upgraded electrics to supply all that. ;)

doodling

Hi,

Do you really need the capability to burn gas at 103kW? Whilst I accept you may have a big house, that is an awful lot of gas (and an awful lot of consequent heat).

Unless your goal is to produce steam, then 35kW will hear substantially more than a "trickle" to a decent temperature.

I would be looking at whether I actually needed 3 boilers. If three boilers were essential then I would be looking to see if suitable control / interlocking arrangements could be put in place to limit the maximum demand such that you don’t need a meter replacement.

Finally, an option might be to consider alternative fuels (electricity, oil, LPG, wood, etc.).

FreeBear

oven = 15kw

boiler = 35 kw

Pool boiler - 18kw

I'm assuming both boilers are system or heat only ?

Unless you have a very large house with a lot of big radiators coupled with a basic thermostat, the only reason for a 35kW boiler is fast reheat of the hot water tank. Most properties do not need 35kW to provide adequate heat.

In this modest 3 bed semi, I used to have a ~13kW back boiler for central heating and hot water via a tank. Replumbed the system a couple of years back and fitted a 30kW combi - That was sized for anticipated hot water flow which turned out to be lower. Could have got away with a 24kW model. For heating, I only need ~7kW peak to get the place up to temperature. Have a heat meter on the flow/return from the boiler, so can monitor exactly how much heat is used.

In your shoes, I'd be going back to your plumber and asking him to justify an additional 35kW boiler - If it is a heat only, then you do not need 35kW. An 18kW (or even 12-14kW) would be ample at the expense of a longer reheat of the DHW tank. Perhaps even look at replacing the existing 35kW boiler with a smaller one.

I'd also second the suggestion to look at installing heat pumps and induction hobs with the view to getting rid of gas completely.

Scot_39

https://forums.moneysavingexpert.com/discussion/comment/82071779#Comment_82071779

Wouldn't going all electric risk the need for a new 3 phase electric connection instead - same digging - if not an overhead line feed currently.

Ectophile

Is a single 20mm pipe really going to be up to the job?

Before I moved out of my flat about 15 years ago, I had to replace the boiler. For whatever reason, the people I chose decided on a 30kW boiler. Probably over-sized for a flat.

The Gas Safe people randomly chose my install for a check. They criticised the excessive pressure drop when the boiler was on. That's one gas boiler on a 20mm pipe.

In this case, the reason for the drop was a long pipe that snaked from the meters on the ground floor to my flat on the top floor.

doodling

Hi,

https://forums.moneysavingexpert.com/discussion/comment/82072314#Comment_82072314

Pipework before the meter may be at a greater pressure than the 20mbar or so that is provided after the meter and therefore higher flow rates can be achieved through smaller pipes.

Exactly what pipework is required before the meter in this case will depend on the flow required and the supply pressure range in the area.

Without more information from the OP, my view is that the optimal solution here will be limiting maximum demand rather than installing a bigger supply.

Largergaspipe45

Thank you very much for taking the time to reply and for requesting this thread to be moved to the correct board - please let me know if threre is sanything I need to do.

£10k seems anhuge amount as it doesn't take into account removing plants; it doesn't tell me if it will go through cobbled stones and electric gate track, likewise with very old, thick stone wall and makes "assumptions" about these in the quote meaning that £10k will be far greater.

When you say "you can supply a U2 meter through a 22mm pipe quity happily" I assume you mean the sizes are U2, U6 and U16. I also assume my gas meter is U6 - what would be the relevance of a U2 meter? Thank you again!

https://forums.moneysavingexpert.com/discussion/comment/82071770#Comment_82071770

Largergaspipe45

https://forums.moneysavingexpert.com/discussion/comment/82071779#Comment_82071779

Thankyou very much for taking the time to reply. In asnwer to your thoughts Changing the hob (the oven itself is electric) to induction is not an option as it is a specific cooker for the space.

There is not space for the storage of the LPG and on a practical level it would not be feasible to be changing them over.

The pool already has an AS heat pump (pool boiler is only used as a small boost if needed during particularly cold shoulder seasons for events or training)

We have 3 phase electric…

Thank you again for your thoughts - if you have others on the basis of my reply please do advise! Very grateful for all thoughts and questions that help guide towards a practical solution!

Largergaspipe45

https://forums.moneysavingexpert.com/discussion/comment/82071840#Comment_82071840

Thank you so much for taking the time to read and reply.

• The poil has an AS heat pump as main heat source and boiler only used if shoulder season particularly cold and pool required for event or training.
• The house is single glazed and radiators are 50-70m+ away from boiler (we have insulated everything as much as possible, loft, filling in joist floors, carpets, shutters, curtains, expandable foam!). We also have an open fire (refurbished with very good draw - and a log burning stove) We have had terrible problems with the heating not reaching the furthest rooms of the house.
• We have 3 rainfall showers that are all used at the same time every day and we run out of hot water after approx 5 minutes in the shower each. When we renovated the house 14 years ago the plumbers put in two water tanks that were far too small for house requirement (turned out it was easier for them to put them in a small loft recess than using main loft and putting in suitably sized). In this latest quote that we accepted from new plumber to address lack of hot water issue we were told that another boiler and separate water tanks in the loft would solve the problem and keep our heating reaching around the whole house.
• (we are waiting for planning to be able to put in electric batteries that, in time, could be connected to solar but we need to acquire the land for the solar! Oil seems too volatile price wise. We manage our wood carefully and heat some rooms with fires. Avoiding the need to replace bottles is important.

Control and interlocking arrangements are what I have read about in my own research but I have no idea how to go about finding someone who could design this/knows about and has dealt with this before - it seems quite niche. I am so relieved to hear someone actually mention these as, based on our relatively short time window for max gas demand, this seems like a more sensible solution! Can you point me in the right direction by any chance? Thank you so much!