New Boiler - Change Of Gas Pipe Required?

[GC72]

I am currently in the process of having a new Greenstar CDi Classic boiler fitted and would be grateful if someone could help me with technical question.

The distance between the gas meter and my boiler (in my kitchen) is between 11 and 12 meters. The gas supply also feeds my oven hob. Will my gas fitter need to run 28mm pipe for the installation?

Also, Is there a calculation my fitter can do to work out the pipe size prior to installation?

Thanks for your help

 

[Dan Robinson]

Will my gas fitter need to run 28mm pipe for the installation?

Probably... Depends on the number of bends and the outputs of the boiler and hob

Also, Is there a calculation my fitter can do to work out the pipe size prior to installation?

Yes.

 

[gblades]

You don't say what size your existing pipe is.
The following information is from discussions with a couple of fitters and is what they said so don't rely on it being totally accurate.

In my house the distances were about the same but the pipe from the meter was 22mm and then it split under the kitchen concrete floor to a couple of 16mm pipes to the boiler and oven.
One fitter measured the gas pressure at the meter and at the boiler to calculate the pressure drop through the system. The conclusion was that if he changed the pipe to 22mm as it came back out of the floor the pressure drop might be low enough across the system to be compliant but it would be close.
The second fitter didn't think having any 16mm pipe in the path would be compliant and gave the only option of running an additional pipe round the side of the house. Due to the number of bends involved he recommended 28mm pipe.

I ended up going with the 2nd fitter.

 

[just pumps]

You don't say what size your existing pipe is.
The following information is from discussions with a couple of fitters and is what they said so don't rely on it being totally accurate.

Needs to be there with eyes and pressure gauge even if the OP knows what the new boiler will be.