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can you calculate water pressure from weir cup reading ?

Postby misery » Tue Aug 05, 2008 10:10 pm

Hi ,
Newbie here and a bit of a novice! Have just moved house which we love but the bathroom is very dated as well as the heating system.
My wife and I have looked at these steam cabin type showers which we like but just the shower version(no steam).We also like those two person jacuzzi baths.
My question is :the shower we like specify that the water flow should be between 13 and 16 litres per minute. A friend of a friend measured our flow wih a weir cup which read a flow rate of 11.5 ltrs per minute.Do the shower companies deliberately hike up the figures to be on the safe side or do you think this would seriously affect the performance of the shower?
My other question is the bath we like specifies a minimum 1.5 bar pressure.The guy who measured the flow rate didnt have a pressure guage or whatever it is that is used ,to tell me what pressure we have.
Can you calculate water pressure from the weir cup reading?
We are shortly having a Heatline C28 combi boiler fitted.
Many thanks.
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Simply Build It

Postby htg engineer » Wed Aug 06, 2008 10:59 am

Before having the boiler fitted, this is when you have to find out the flow rate required.

The flow rate will be regarding the hot water, so your old boiler flow rate may be poor - but install a boiler with a better flow rate - and your problem is sorted.

As for the pressure, buy a pressure gauge from screwfix, attach to the cold washing machine valves, and it'll tell you the pressure.

The Heatline C28 only has a flow rate of 11.24l - so no good for you. Nothing you can do with it after installation - that's the flow rate, and the flow rate will decrease over time if you don't fit a scale inhibitor or similar to prevent the heat-ex furring up.

I know the Heatline boiler is cheap (£380-£400) but there's S**** cheap boiler (like heatline) and good cheap boilers. Baxi, Potterton, you pay abit more (not much), but a much better boiler.

htg engineer
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Postby misery » Thu Aug 07, 2008 7:07 pm

thnks htg engineer,
have borrowed a pressure guage today and it reads 3 bar,so no problem with the bath we want.The problem is have already bought the boiler so stuck with it really,hope not too much of a silly question but the shower cabin we want has about 8 jets on it in total monsoon shower,body jets,foot wash etc,we probably wont have all these on most of the time,so the difference between 13 lpm and 11.24 lpm hopefully wont make that much difference if mainly using just the shower head,do you agree,you may ask why we are buying it if not going to use all yhe features? its just that we like it having looked at loads of other models.
Any further advice greatly appreciated,cheers.
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