Any way to 'actively' test whether gas flow is adequate?

[DevsAd]

Bro has a system boiler which he'd like to replace with a combi. He's on the 5th floor of a building and the gas metres are at ground level.

The gas pipe route seems to be up the outside of the building for most of its way, then comes in and travels up to a 'room' on the roof where the system boiler was fitted last year.

I know that combi boilers consume more gas than conventional boilers when 'instantly' delivering their DHW, and I understand that determining the correct gas pipe sizing is usually done using calculations - length, bends, kW of appliances etc.

But is there any way for a GasSafe to actually measure the actual existing gas flow at the boiler to determine whether it's adequate for a combi? Eg - measuring the max deliverable flow from the pipe? Or are calcs the only way?

(I'm thinking that calcs could be long-winded in this case as following the pipe route is a bit torturous. And it's also a looong way; 5m to get from the front of the building to the back, 20m min going up to the 5th floor, back in to the flat, another few metres upstairs...)

All the flats below do appear to have had combis fitted (they've all had their CWS's removed from the roof), so presumably they've either had adequate pipe sizes from the off or have had them replaced.

If the existing pipe to the top flat is found to not be adequate, is the only answer to replace it with a larger pipe size, or can Transco(?) or similar 'tweak' the meter's output slightly?

Thanks.

 

[townfanjon]

with the pipe work there , yes it’s probably correct but not 100%, your installer will know how to do the necessary checks if the existing boiler is still working , but I cant tell you how on here because its against the rules .

 

[DevsAd]

with the pipe work there , yes it’s probably correct but not 100%, your installer will know how to do the necessary checks if the existing boiler is still working , but I cant tell you how on here because its against the rules .

Thanks.

That's all I was after, Jon - that is was possible to actually check that the flow is suitable rather having having to measure numerous lengths of pipe and do the calcs.

The new system boiler is working fine, but when my bro had it fitted last year, we explored at the time whether there was a way to fit a combi instead - ie with a small mains booster pump feeding it - but the plumber dismissed the combi as the gas supply was 'unlikely' to be adequate. He carried out no tests to my knowledge, hence me asking if there is something he could have done to check it as we are now definitely after a combi if possible (new mains booster/store being installed).

So, it can be 'dynamically' tested?

Thanks.

 

[townfanjon]

Theres a few iffs and buts, but it would give a good indication.

 

[sammathias]

Being on the 5th floor i would imagine atleast part of the supply pipework would need upgrading.

 

[Vee]

Why not go for a thermal store. Can use the existing boiler. Space of cylinder being replaced with store. Much better flowrate performance.
Look at the ones without the fancy bits. Work well. BoilerMate BP | Gledhill

 

[DevsAd]

Thanks all.

The whole reason for going combi is that a location for an unvented cylinder of any type would be awkward - no easy way of providing a gravity drain for it. A combi would be much easier, and it is only a 1.5 bedroom flat with one bath/shower.

Cheers, here's hoping the plumber is prepared to do the necessary to check the flow.

 

[Riley]

Most decent gas engineers would be able to do a rough *** packet Calc to know if gas pipe will need upgrading. I would always do it again properly to be sure.