Q for RGI's - Fitting boliers on common supplies...

[BoxBasher]

For you Corgi's out there. Is there any regulation (from a gas installation point of view) that prevent the installation of a Combi (or other boiler for that matter) on a common (shared) supply pipe or an old lead supply with poor flow?

Or to word it differently - is there a requirement to ensure that a new boiler will receive the minimum pressure and flow of water to enable it to operate
i) correctly
ii) Safely
iii) Efficiently

Just so I have another tedious reg to add to my incedibly accurate (but in no way helpful) armoury of smartarse replies when confronted with a customer saying "BG have been back out and they say its the water pressure causing the problem..."
Surely it's the same water pressure that was there before they fitted the damn thing?

 

[corgiman]

only MI's mate

if the rate isnt what the manufacturers state is their minimum then dont fit it

on the practical side if its poor then the customer aint going to happy so dont fit a combi

 

[BoxBasher]

only MI's mate

if the rate isnt what the manufacturers state is their minimum then dont fit it

on the practical side if its poor then the customer aint going to happy so dont fit a combi

Cheers Corgi - I don't fit them.

I'm one of the poor fella's that the Water Co sends out and has to explain that the pressure and flow are above industry and company minimum levels and that the boiler should work (or they should have fitted one that does).
Problem is people think BG can do no wrong and that it's the big bad water co that is trying to wriggle out.


Is there a requirement to install stuff to the MI's as gospel?

 

[corgiman]

yep there is

and the water company BY LAW only have to supply something like 9 ;itre per minute at 1 Bar

I am probably wrong and sure someone will correct the above in NO time

If BG fitted a Combi on a main without adequate flow/pressure its their look out, but if they can prove that they checked it before they fitted! gawd knows

 

[Agile]

When I complained about the pressure and flow from my shared supply coming across the back garden from the neighbour the S-T man said they only had to provide 6 li/min open pipe and 0.6 Bar static pressure.

As far as fitting a combi is concerned a little interpretation has to be applied.

As little as 0.2 Bar will usually give a little flow through the boiler!

Its not dangerous to have too little pressure or flow to a combi just useless performance.

O.6 Bar is really below the system pressure I would advise so a pump would be advised for topping up.

Tony

 

[BoxBasher]

and the water company BY LAW only have to supply something like 9 ;itre per minute at 1 Bar

Dynamic reading of 9 litres/minute at 1 bar at the boundary is the minimum standard of service required by the regulator. Any property receiving less must be reported to the regulator (Ofwat). I can't imagine what the internal supply would be like if the boundary was only getting 9lpm@1bar though.

The statutory minimum is 7 m/head (0.7 bar) anything below this level for a period of 1 hour or more, twice in a 28 day period is entitled to compensation (unless they live within 7 meters of the top water level of the service reservoir supplying the area).

Although it is my job to know these things, I have never been able to understand why the "minimum standard" is actually above the "legal minimum". What happens between the two I honestly don't know...

 

[BoxBasher]

yep there is

Is there a number relating to the reg or is it just "known"?

 

[BoxBasher]

When I complained about the pressure and flow from my shared supply coming across the back garden from the neighbour the S-T man said they only had to provide 6 li/min open pipe and 0.6 Bar static pressure.
Tony

Where would that reading be taken Tony? I don't know anybody who can accurately calculate the head/flow loss along a given length of pipe of unknown condition to enable an exact pressure and flow to be measured at any point other than at the boundary.

I think the ST guy was trying to fob you off.

We usually take a reading from the first incoming cold tap because if it meets standard here then the boundary levels must be higher.

If it fails at first tap we usually relay the comunication pipe (between main and boundary) and test the pressure at boundary. If it passes here then the problem is a restriction within the bore of the service pipe (private responsbility)

 

[ChrisR]

I know a chap who converted to a Megaflo and built a loft conversion with a shower , only to find that the mains pressure wasn't enough for any water to come out of it.
Did I larf? You could say so...

 

[corgiman]

yep there is

Is there a number relating to the reg or is it just "known"?

I am too fat and lazy to check it but it is a given that all RGI's follow the boiler MI's above all things

I am sure there is a reg for it but cannae remember it off hand

 

[BoxBasher]

Tony,

For your information.

Here is a document (in the public domain) from Severn Trent. Page 7 may be of use to you.

"we are required to report to the Director general those properties that are at risk of receiving less than 10 metres head (1 bar) of pressure whilst receiving 9 litres flow per minute"

Don't know where he got the 0.6bar & 6 l/min from but I've a feeling he just plucked them out of the air (because it is about what you are getting?)

If they are providing adequate supply to the boundary then it's down to you (new single supply) but they should investigate properly rather than taking the p*ss...