How do I know if there's a 20mm incoming gas main?

[AssuredHeating]

Ok, so today it's seems I've made a massive cock up. A while back a client asked me to recommend a combination boiler for installation.
I recommended a Worcester 34cdi, that seemed to be suitable for his property, 30kw CH, 34kw HW, however the client had loads of cold water flow so I said he could also go with the 38CDi for a better HW flow rate.
The 38CDi was installed, nice easy job, came to commissioning put the boiler at full rate, and got 10mbar working pressure at the meter. I got straight on the phone to Transco to check the governor, they came round saying it needed a bigger supply pipe as it's only 20mm. I thought no matter what boiler I put in, they have to give me atleast 19mbar working pressure, it turns out I'm wrong.
The clients have recently had this 20mm installed, and apparently the 20mm was specified by National Grid as that would provide enough pressure for the existing system.....So I should of checked the 20mm pipe and put a same rate boiler back in.
People these days require more and more HW flow rates for a better shower, boiler manufacturers are making bigger boilers to meet the need, why are Transco not future proofing their installations by simply installing a 25mm pipe!
I can't be the only installer not to check the incoming mains pressure at the quotation stage?.

 

[Killy Bing]

Are they rural? Fed from their own meter pit?

medium pressure would sort it but i wouldent know to go about sorting it.

what's the pressure service side?

 

[AssuredHeating]

Are they rural? Fed from their own meter pit?

medium pressure would sort it but i wouldent know to go about sorting it.

what's the pressure service side?

Hello, thanks for your reply.

its a well built up area.

The latest is National grid are going to move the gas meter to the front of house to make the 20mm underground a shorter distance, then they will run 35mm copper from the meter to the loft, 28 across the loft then 22 into the boiler, it's going to look terrible! And they say they may not even get enough pressure at the governor then. We have to do simple pipe sizing calculations for our internal pipe work, how come they can't do a pressure loss calculation from the road to the governor???

 

[E4gas]

Are you gas safe !

 

[AssuredHeating]

Of course I'm Gas Safe

 

[Billy Bob Bob]

the utilities are coping out,they have to provide min 19mb this is fact,i have had them run new lines before when they have run plastic up the old metal pipework

 

[Billy Bob Bob]

Are you gas safe !

he sounds like he is to me and i think transco are taking the proverbial

 

[AssuredHeating]

My replays don't seem to be showing......

 

[E4gas]

Ive had yellow filings from transco blocking the incoming ECV , it's when they tap in to the main ,

 

[Ermintrude]

Yeh we get few of poor insertion jobs where pressure is pap. But usually it's water or guff in mains. Where is that Jefaz he should be able to provide answers as he's employed by trannys. Notice how I didn't say he worked for them!