What mains pressure do water companies have to supply?

mart.vader

southcoastrgi wrote: »

you are measuring it wrong, it doesn't matter what pressure you have without anything running, you need to connect the gauge to your outside tap & run the cold on your kitchen tap (providing that's connected to the mains) then see what pressure you have, that's the pressure you go by

That's news to me. It's certainly not the method used (as far as I know) by water cos.

mart.vader

Come on, southcoast, corrie must have finished by now !

diywhynot

MV: Static (standing) pressure vs. dynamic pressure.

mart.vader

diywhynot wrote: »

MV: Static (standing) pressure vs. dynamic pressure.

Er, thanks.

Which method do the water cos comply with ?

diywhynot

mart.vader wrote: »

Er, thanks.

Which method do the water cos comply with ?

Minimum static water pressure of 10 metres at the stop tap at the boundary to your property. The dynamic pressure will be less than the static pressure = potential nightmare. For example, combi boilers installed without sufficient mains pressure and flow is becoming a common problem.

mart.vader

Static water pressure ?

So does that mean the pressure you get on the gauge without anything running ? ?

What do you think, southcoast ? ?

ValHaller

mart.vader wrote: »

Static water pressure ?

So does that mean the pressure you get on the gauge without anything running ? ?

What do you think, southcoast ? ?

HappyMJ's link says static.

HappyMJ wrote: »

7 metres of static head in the communications pipe. Basically at ground level.

http://www.ofwat.gov.uk/consumerissues/rightsresponsibilities/standards/gud_pro_gss08.pdf

southcoast will no doubt answer for himself, but I can see the sense in what he does - if the pressure is not maintained under flow, then even if you do have the 0.7 bar static, the flow will probably be useless for a combi or for very much really.

mart.vader

The OP has not mentioned and is not bothered about a combi boiler.

They say that their mains-fed electric showers are not working due to low pressure. They also want to know what the minimum pressure is, that Water Cos are required to supply, and are also concerned that they might have a leak.

Yes, HappyMJ's link does say static. This means the pressure is taken when there is nothing else running.

On the other hand, southcoast says "you are measuring it wrong, it doesn't matter what pressure you have without anything running, you need to connect the gauge to your outside tap & run the cold on your kitchen tap (providing that's connected to the mains) then see what pressure you have, that's the pressure you go by"

Water Cos, minimum standard is static pressure not dynamic pressure. If you (or southcoast) want to argue with them and claim that they are doing it wrong, and they should measure it as southcoast describes, then Good Luck to you with that !

If you're right, the Water Cos accepted minimum of 0.7 bar static, would be useless for combi's as, when anyone turned a tap on, their combi won't work.

ValHaller

mart.vader wrote: »

The OP has not mentioned and is not bothered about a combi boiler.

Electric showers and combi hot water are about the same power and the same flow, so what is good for one is good for the other, I am just explaining the sense of what southcoast does,

diywhynot

ValHaller wrote: »

Electric showers and combi hot water are about the same power and the same flow, so what is good for one is good for the other

You might want to rethink that.