Possibly daft questions re water pressure

[Pat53]

Hi,

I'm just a householder, trying to understand my options for upgrading my CH and DHW system and hoping somebody here in the trade can help me.

I understand that thermal store and unvented cylinders can only deliver hot water at mains pressure, so if the mains pressure is low they won't improve the hot flow.

But I don't know how to measure the mains pressure...how please?

Secondly, my mains cold water is quite forceful enough for a good (but cold) shower; it seems to me that the hot water from one of these systems would therefore also be forceful enough so I could get a nice warm and sufficiently powerful shower without actually having to know the pressure...or am I missing something here?

thanks in advance

 

[Hows-it-hanging]

The water broad will test the mains pressure for free .They have got a cup that is put under the tap that has got holes at different heights on the cup that will test the pressure of flow . If water just comes out of the bottom of the cup the pressure is low. If it comes out of the bottom and the top of cup holes its good pressure.

 

[ChrisR]

The water broad will test the mains pressure for free

Not with a Flow Cup she won't

You can buy a gauge for about £12 to measure the pressure, you just screw it on say the garden tap. It's quite a good idea to be able to measure at different times of day because it can drop a lot at the times when everyone ois using it - and you want it.

Flow you can measure with a bucket and a watch.

Assuming you only have one bathroom, yo need a minumum of say 2 bar pressure, and 18 litres/minute flow from cold kitchen sink and outside tap combined - put them both on full and see what you can collect in a minute.

If you put the kitchen tap on full and the garden tap coming on reduces the kitchen tap flow much, you have resistive pipes. Can be old half inch lead, bashed and kinked all along.

If you have more than one bath or shower, you'll probably need a new mains pipe from the road to reduce the flow resistance.

 

[Hows-it-hanging]

They did it at my home with a cup for free.

 

[BoxBasher]

yo need a minumum of say 2 bar pressure, and 18 litres/minute flow from cold kitchen sink and outside tap combined - put them both on full and see what you can collect in a minute.

I only get 15 litres/min from my lovely new 25mmPE pipe, although it does drop to 15mm copper straight after it comes in and then goes all the way from bathroom to kitchen...(bungalow)

Industry standard is 9litres/min at a working pressure of 1 bar (10 metres/head).

 

[Hows-it-hanging]

why pay for the teat when you can have it done for free by the water broad?

 

[ChrisR]

why pay for the teat when you can have it done for free by the water broad?

I have already explained that.

The pressure varies throughout the day. OK?
--

BB is quite right of course that the minimum statutory pressure and flow are far too low for anything much at all.
As the Water Providers are "managing" their pressures better (downwards) to reduce losses due to leaks, heaven knows what we'll all end up with. Tanks in lofts, I suppose!

With only 15 litres a minute available, investment in an unvented HWSS wouldn't be a huge success.
What's your pressure like BB?

 

[BoxBasher]

why pay for the teat when you can have it done for free by the water broad?

Who is this broad? Seems an accomodating lass doing teats for free

Problem with Water Co test is that they will come and test it once, usually in the middle of the day. You really want to know what it's like at 7am when you're trying to get a shower before work, or on Friday tea time when your missus wants to run a bath before going out. You wan't to know if you can fill a washing up bowl on a sunday when all the old people (who could do it in the week without bothering anyone) wash their cars...