Search the forum,

Discuss Length of gas pipe from meter to boiler in the Gas Engineers Forum area at PlumbersForums.net

Messages
3
I have a domestic gas meter located at one side of my building and my boiler/cooker (only 2 gas devices) on the other side of the building. There is currently a 28mm gas pipe from meter to the boiler which is approx 25m and a further 5m to the gas cooker. My gas engineer is saying that the installation is non compliant (BS6891) and that I must get the meter moved to be close to the boiler which will cost a huge amount of money and I would need to dig a 25m channel through concrete and get Cadent to then move the meter. Is this correct? Is there another lower cost solution (eg: larger gas pipe?) Thanks for your advice.
 
Did he state why it’s non compliant?
 
Just said that the distance from meter to boiler is too far. Something about pressure loss.
Maybe get another opinion by someone who can pipe size? 35mm is probably the next size up, if that’s unsuitable then you’re probably looking at the meter, supply et al.
 
Just said that the distance from meter to boiler is too far. Something about pressure loss.
Need to upgrade to either next size up eg 35mm or 42mm etc a gas engineer can work this out you may need a commercial one due to the size
 
There may be a loophole for you.

I've done this a few times.

Test the suspect gas appliance operation / pressures while the appliance is running.
If the inlet gas pressures doesn't drop while the appliance is running, then you can deem that the gas pipe size / pressure is adequate.

You will have to make sure the boiler is rated at the expected kW output required.

eg: 24 kW boiler installed.
Heating required from boiler - 20 kW.

You make sure the gas burnt by the boiler equates to the 20 kW, not the 24kW
 
What kw is the boiler?
Is the cooker all gas or duel fuel?
 
There may be a loophole for you.

I've done this a few times.

Test the suspect gas appliance operation / pressures while the appliance is running.
If the inlet gas pressures doesn't drop while the appliance is running, then you can deem that the gas pipe size / pressure is adequate.

You will have to make sure the boiler is rated at the expected kW output required.

eg: 24 kW boiler installed.
Heating required from boiler - 20 kW.

You make sure the gas burnt by the boiler equates to the 20 kW, not the 24kW

You can’t have more than 1mb drop from meter to appliance.

You have to run the appliance at max, you can’t down rate it.

So I don’t understand what this “loop hole” is?
 
Vaillant Boiler is rated at 37kW and Cooker (4 burners plus oven) totals 30kW

EDIT: the calcs are wrong, had the app set to 25 feet, not meters.... pipe is too small.... Good catch Shaun.


It looks like you’re probably not much over, dependant on how many fittings have been used.

Roughly, 67kw at 25m and 14 high loss fittings comes out at 1mb drop in 28mm pipe.

Is there a gas test point under the boiler or did they test at the gas valve inside the boiler? If they tested at gas valve, it will add anywhere from 1mb-2mb on the reading.

If a reading from a test point under the boiler was 2.5mb, I’d agree but at the gas valve, I’d want to install a test point.

As above, I’d get someone else in who can pipe size and get a test point installed under the boiler.

Also, either way, because I think you’re pretty close to 1mb (depending of number of fittings), is there any exposed gas pipe? Or can you get to any relatively easily (under floor boards etc)? If so, a section could be ungraded to 35mm.

The whole pipe doesn’t need to be 35mm. It doesn’t even need to be the beginning section. Gas doesn’t care where the section is.

You also need to be careful not to upgrade the whole pipe (more than is needed) or the total volume will make it commercial. This is likely the reason the engineer told you to move the meter closer. I guess they don’t have a commercial ticket and don’t want to lose the business. Or they struggle with pipe sizing.

Out of interest, where in London are you?
 
Last edited:
You sure Timmy quick *** packet gives me a drop of 0.8 on 35mm with 14 high bends
 
You sure Timmy quick *** packet gives me a drop of 0.8 on 35mm with 14 high bends
Ooooo gonna check again.....

Good catch Shaun, I had the app set on feet.....not meters.

Just got the same outcome as you.

That changes things....
 
You can’t have more than 1mb drop from meter to appliance.
to 20k
You have to run the appliance at max, you can’t down rate it.

So I don’t understand what this “loop hole” is?
Loop Hole is, that if you can prove the appliance is working correctly with the correct gas pressures , you may get away with a slightly undersized gas service line.

As stated previously, if you by a 24kW boiler and only require 20kW, commission the appliance to 20 kW and see what your pressure drop is at the appliance.

Is a Gas Inspector going to re calibrate the appliance to maximum and then test the gas line for correct pressures?
 
Loop Hole is, that if you can prove the appliance is working correctly with the correct gas pressures , you may get away with a slightly undersized gas service line.

As stated previously, if you by a 24kW boiler and only require 20kW, commission the appliance to 20 kW and see what your pressure drop is at the appliance.

Is a Gas Inspector going to re calibrate the appliance to maximum and then test the gas line for correct pressures?
This won’t work with a Combi boiler, as you can range rate the heating but the hot water will be the higher output.
 
Loop Hole is, that if you can prove the appliance is working correctly with the correct gas pressures , you may get away with a slightly undersized gas service line.

As stated previously, if you by a 24kW boiler and only require 20kW, commission the appliance to 20 kW and see what your pressure drop is at the appliance.

Is a Gas Inspector going to re calibrate the appliance to maximum and then test the gas line for correct pressures?

I understand that people regularly let a slightly undersized gas pipe pass.

However, to complete commissioning, you need to test the gas pressure on max load, not partial. On a new install I’m installing a test point under the boiler and running other appliances. I’m not letting an undersized gas pipe slide.

However, I’d size the pipe and new boiler demand and know if it needs an upgrade when quoting work (and include the gas upgrade).

Loop Hole is, that if you can prove the appliance is working correctly with the correct gas pressures , you may get away with a slightly undersized gas service line.
Got a source?
 
I understand that people regularly let a slightly undersized gas pipe pass.

However, to complete commissioning, you need to test the gas pressure on max load, not partial. On a new install I’m installing a test point under the boiler and running other appliances. I’m not letting an undersized gas pipe slide.

However, I’d size the pipe and new boiler demand and know if it needs an upgrade when quoting work (and include the gas upgrade).


Got a source?
In new installs, I generally oversize the gas supply pipe.

In existing houses or premises, where the gas supply pipe is borderline to the requirements, things can be done to alleviate the installation of a new gas line.

If the appliance works correctly with a slightly undersized gas supply and you can prove the appliance is working correctly, then there isn't an issue or a necessity to replace the gas line.
We have inspections from auditors on some jobs. At times they will question whether or not the gas supply pipe is the required size.
Operate the appliances and test the inlet gas pressures and if they prove to be adequate - end of story.

I have at times reduced the output of heating only boilers to get the gas supply over the line.
Unless the customer is going to add extra panels or add other gas appliances, then the existing gas supply is adequate.

But that will be up to the person doing the works, whether it me me or someone else
 

Reply to Length of gas pipe from meter to boiler in the Gas Engineers Forum area at PlumbersForums.net

Creating content since 2001. Untold Media.

OFFICIAL SPONSORS

OFFICIAL SPONSORS

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock