Huge gas pressure drop between meter and boiler. Help!

[davecon70]

And interesting, maybe I spoke too soon about the plumber not having been naughty. Just found an online calculator here http://www.gb-gas.co.uk/clc/pipesize/GAS PIPE SIZING 2016 WEB.htm, says it's the 2016 version, also says that 5m of 15mm would cause a (not permitted on installation) drop of 2.28mBar at full boiler load

I am certain that the plumber just connected up the old pipes and didn’t check to see anything else as seemingly it wasn’t an issue in the past. Easy work and payday but he would argue that it would have been more expensive to change the pipe work etc.

 

[FiremanT]

I don't think he was suggesting one dies that with gas, he was talking about cars.

Though to be honest my experience with both suggests I'm better off doing both myself.

Although as luck would have it I have since found a very good gse that is able to think for himself and fix issues without just chucking parts at it, which is a rare occurrence.

Still trying to find a decent mechanic that has retired...

It doesn’t matter which trade , the average Joe does not have the knowledge or kit to identify faults properly.
As for GSE’s, there are some part chuckers, but there are also a lot of skilled and experienced guys, so your comments are a bit insulting

 

[FiremanT]

I don't think he was suggesting one dies that with gas, he was talking about cars.

Though to be honest my experience with both suggests I'm better off doing both myself.

Although as luck would have it I have since found a very good gse that is able to think for himself and fix issues without just chucking parts at it, which is a rare occurrence.

Still trying to find a decent mechanic that has retired...

It doesn’t matter which trade , the average Joe does not have the knowledge or kit to identify faults properly.
As for GSE’s, there are some part chuckers, but there are also a lot of skilled and experienced guys, so your comments are a bit insulting

 

[FiremanT]

I don't think he was suggesting one dies that with gas, he was talking about cars.

Though to be honest my experience with both suggests I'm better off doing both myself.

Although as luck would have it I have since found a very good gse that is able to think for himself and fix issues without just chucking parts at it, which is a rare occurrence.

Still trying to find a decent mechanic that has retired...

When you say “retired “, you mean “cheap”?

 

[FiremanT]

Yes that's helpful. If I've read the manual correctly, at max output it can use 3.2 cubic metres of gas per hour so that's one figure. The big old pipe from the meter (copper hopefully)- can you see what size it is when it goes into the floor and when it comes out? Quite important to be accurate on the size- big difference in pressure drop between 22mm and 28mm. Last one- how long is the length of 15mm from boiler to old (larger bore?) pipe, or does the 15mm vanish under the floor

its an eco tec plus 630. As you can tell I’m out my depth here but looking T the boiler feeds it a 15mm pipe going in and big old pipe pipe at the meter. Looks almost double the thickness. The gas feeds the cooker (5m away on same floor) and the boiler is on the first floor and got to be at least 13m from the meter. Not sure if that helps?

Is the big pipe copper ? It may be iron. If you are not sure, try a magnet.

Your installer / serviceman did the install wrongly, and the only question is does he actually know ? Tell him to rectify at his cost or you will call Gas Safe and ask them fir a free inspection. They will require him to rectify ANY errors that he made.

 

[davecon70]

And interesting, maybe I spoke too soon about the plumber not having been naughty. Just found an online calculator here http://www.gb-gas.co.uk/clc/pipesize/GAS PIPE SIZING 2016 WEB.htm, says it's the 2016 version, also says that 5m of 15mm would cause a (not permitted on installation) drop of 2.28mBar at full boiler load

I am certain that the plumber just connected up the old pipes and didn’t check to see anything else as seemingly it wasn’t an issue in the past. Easy work and payday but he would argue that it would have been more expensive to change the pipe work etc.

Is the big pipe copper ? It may be iron. If you are not sure, try a magnet.

Your installer / serviceman did the install wrongly, and the only question is does he actually know ? Tell him to rectify at his cost or you will call Gas Safe and ask them fir a free inspection. They will require him to rectify ANY errors that he made.

The pipe that feeds off the meter must be iron as a weak magnet stuck to it. Is that good or bad? Other than the height clearance why do you think he installed incorrectly. He will argue he just replaced the boiler in situ.

 

[Deleted member 267285]

And interesting, maybe I spoke too soon about the plumber not having been naughty. Just found an online calculator here

Calculator could be wrong, pipe sizing did change, I just can’t remember when.

 

[kidgreen61]

If I came across this, I'd spend 2 minutes putting a test tee in just before the boiler to know exactly what I'm dealing with, having tested WP on other appliances first.

 

[Harry Bloomfield]

The pipe that feeds off the meter must be iron as a weak magnet stuck to it. Is that good or bad? Other than the height clearance why do you think he installed incorrectly. He will argue he just replaced the boiler in situ.

It is potentially bad, depending on the OD. Steel pipe is much thicker walled than copper, so less space for gas to flow.

 

[kidgreen61]

Ignore the DIYers advice, if the gas pressure has suddenly dropped, then there's a reason for it.

 

[Harry Bloomfield]

The pipe that feeds off the meter must be iron as a weak magnet stuck to it. Is that good or bad? Other than the height clearance why do you think he installed incorrectly. He will argue he just replaced the boiler in situ.

If a heat only boiler was installed and it was replaced by a combi, the combi will be designed to have the heat capacity to heat up your hot water instantly, on demand. That means a boiler of perhaps double the Kw rating, double the Kw, double the gas flow too.

If you light your gas oven, gas hob, or gas fire, with the boiler not firing, if your then trigger the boiler to fire, does the oven/hob flame height decrease?

 

[ianmcd]

it was the same plumber\GSE that installed it and serviced it last year. Do you think it’s worth calling British Gas?

Why the fook would you call British Gas ? they are an independent company, nothing to do with you gas supply or meter

 

[davecon70]

Why the fook would you call British Gas ? they are an independent company, nothing to do with you gas supply or meter

sorry. I thought someone suggested that I contact the company that provide the gas supply!

 

[ianmcd]

sorry. I thought someone suggested that I contact the company that provide the gas supply!

If you think your supply is the problem you need to contact your transporter, will be possibly SGN, cadent, National Grid, wont be British Gas

 

[fixitflav]

And interesting, maybe I spoke too soon about the plumber not having been naughty. Just found an online calculator here http://www.gb-gas.co.uk/clc/pipesize/GAS PIPE SIZING 2016 WEB.htm, says it's the 2016 version, also says that 5m of 15mm would cause a (not permitted on installation) drop of 2.28mBar at full boiler load

I'd go along with the 2.28mb for 5m of 15mm pipe at 3.2m3/h (which gives about 35kW input).
It's the 8m buried section that's unclear. 1" steel pipe has OD 34mm, so it could be that. Using actual bore 28mm gives pressure drop only about 0.15mb, so total about 2.5mb.
The explanation for the observed 6.5mb might be that the pressure at the boiler is measured at some internal point, not on the supply pipe, as Fireman T suggested earlier. Worth discussing with the guy.