Poor pressure from new shower

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We’ve just had our bathroom renovated and have had a new thermostatic shower fitted with a rain head and smaller handheld head. Both of these have extremely poor pressure.

Our boiler is a baxi 33kw with a flow rate of 13.5 l/m.

I tested the flow rate of all of the taps in the house and the shower (I don’t know what I’m doing at all so just blasted them all on cold)

We are getting 11 l/m from our ancient kitchen tap.

9 l/m from the bath tap (this is about what the expected flow rate is)
6 l/m from the basin tap (expected flow rate is 5 l/m so actually over performing).

And only 6 l/m from our new shower (I only checked the handheld head). If I turn the handheld shower head upside down the water rises about 6 inches! If I did this with our old shower it would’ve almost hit the ceiling! The paperwork from the shower states 12 l/m at 1 bar, which is what our boiler is at. So it is underperforming by 50%!

I’m now wondering what has gone wrong. We’ve moved the position of the shower so it’s different pipework, so is it possible the plumber has done something to cause this, or could it be the shower?

I’m absolutely gutted as didn’t spend thousands to get a lower quality of shower.
 
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The pressure from your boiler pressure gauge has nothing to do with the pressure of the hot or cold water supplies. It's the pressure within the sealed central heating circuit.

Test the pressure (not flow rate) of your cold water main. If this is less than 1 bar, you can't expect to get 12 lpm flow from the shower.

You could test the flow rate from the shower with the head removed. If this is significantly more than with the head attached, it suggest the head needs cleaning. Unlikely with a new appliance. Worth testing the flow rate from the rain head, easier to do if you can remove the head, otherwise spray into a bucket and time it.

Let us know the results from the above.
 
And only 6 l/m from our new shower (I only checked the handheld head). If I turn the handheld shower head upside down the water rises about 6 inches! If I did this with our old shower it would’ve almost hit the ceiling!
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There was obviously nowt wrong with the pressure / flow rate before the " plumbers " re furbed the bathroom. You should get them back to sort out whatever they have done to leave you with the inadequate shower that you now have.
 
Probably a load of muck in the pipes, might need flushing through and reconnecting
 
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We’ve just had our bathroom renovated and have had a new thermostatic shower fitted with a rain head and smaller handheld head. Both of these have extremely poor pressure.
Was the shower mixer the choice of the installer ?

Has the installer been back to rectify the situation :idea:
 
Thanks all. I don’t have a pressure gauge to check the mains pressure, unless there’s another way of doing it?

The bathroom fitters have been back today sorting other issues but the plumber wasn’t here (it’s a family business) so apparently he’ll be giving me a ring tomorrow.

Get the feeling I’m going to be fobbed off, is it possible it’s unrelated to the plumbers work? I never thought I’d be wishing for my mouldy old shower back!

I chose the shower, it’s this one https://victoriaplum.com/product/orchard-wye-black-thermostatic-bar-valve-shower-system

The minimum recommended bar is 0.5 with a flow rate of 11 l/m at 38degrees. The bathroom guys agreed I’m only getting 6.

I know flow rates and pressure are different things, but surely even if the flow was restricted the pressure should be half decent? We seem to have neither pressure or flow!
 
I know flow rates and pressure are different things, but surely even if the flow was restricted the pressure should be half decent? We seem to have neither pressure or flow!
Static Pressure is only relevant to get the water to the top of your house and it only exists with all taps off.
Dynamic pressure is what you need, and that's based on the flow rate and any restrictions.
If the flow is restricted the pressure will be great upstream of the restriction, but downstream it will be insufficient for a decent flow.
 
Thankyou. I’m getting very confused, I need the most layman of layman terms!

I’ve just tested the flow rate from the rain head (only 5 l/m)
And I’ve removed the head of the handheld shower and was getting 8 l/m. Still not great but wondering how I’m losing 2 l/m inside the head?
 
Have come across newly installed showers with poor flow,its either flow reduction in the shower mixer valve or the hot & cold water feeds are restricted.

Turn off hot&cold water,remove mixer valve,get someone :cautious: to hold a bucket in front of the pipe/connection stubs.Fully Turn on hot & cold water and measure the flow rate if necessary.
Pic below shows poor flow.
flow shower.jpg
Person holding bucket will now be very wet :!:
if there is good flow on both connections then the restriction is in the shower mixer valve.
 
Static Pressure is only relevant to get the water to the top of your house and it only exists with all taps off.
Dynamic pressure is what you need, and that's based on the flow rate and any restrictions.
If the flow is restricted the pressure will be great upstream of the restriction, but downstream it will be insufficient for a decent flow.
Agree, seen 6bar static come out of pipe at 0.6bar dynamic!
 
As old & Bold but when you have shower off the wall look in the inlets to the valve for a pair of filters and (hopefully) clean the muck out.
 
Hi again, I had my plumber back this morning and he removed the shower from the wall and checked what was coming out of the pipes. It was 12 l/m, so at some point between entering and leaving the shower the flow rate is dropping by 50%.

He checked the valves/filters and all was clear and looked good apparently.

Is this likely to be a faulty shower?

Thanks!
 
Ps, he checked the bar of the mains and we are getting approximately 1.5 bar
 
Sorry but search 'wye' in the above search box,sorry cant say any more today :idea:

But ask your installer to write a report and you could return the item for a full refund,your professional installer will need to submit reasons for return.
 

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