Poor pressure from thermostatic mixer

[matthewjsummers]

Hi everyone

I have just replaced the shower mixer in one of our bathrooms with this

http://www.victorianplumbing.co.uk/...ic-Bar-Valve-Bottom-Outlet-Chrome-VBS001.aspx

The hot water pressure out of tap is excellent - just had a new 40kw combi installed delivering 16lpm. Pressure out of the mixer is okay but not what it could be.

Is it because the mixer is cheap? We have 2 more to fit and am wondering about trying more expensive mixers if this is cheap? If not, has anyone any idea if it can be adjusted?

Thanks
Matt

 

[flameport]

What size and type of shower head?

By pressure, do you mean flow? Have you measured it?

In any case, a combination boiler with 3 bathrooms is a total fail.

 

[mwerty]

Hi

It's a 10cm diameter shower head, not sure of the make. Fairly cheap though, about £15 for the head.

There are only two of us in the house so combi boiler is fine - the boiler easily supports two showers at the same time, but my question was more about whether anyone had an opinion on whether a cheap thermostatic mixer can affect the pressure?

 

[dilalio]

Where did you measure 16l/m?
Where is this shower head in relation to that? What can your boiler output: temp/litres per minute?
Are you evaluating shower output whilst additional draw offs are being used?

 

[mwerty]

Sorry - I meant flow, by the way, not measured it yet.

 

[ianmcd]

as already advised its flow rate you are talking about, you need to measure it pressure means nothing

 

[mwerty]

OK, so kitchen sink flow rate is 10.5l/m @ about 60 degrees C. Shower flow rate is 6.6l/m @ same temperature.

 

[Tay7]

Might be your hoses especially if it came with a cheap head.

Cheap ones tend to be really narrow bore which is restrictive. You can get wide bore ones to replace.

 

[dilalio]

OK, so kitchen sink flow rate is 10.5l/m @ about 60 degrees C. Shower flow rate is 6.6l/m @ same temperature.

And where is shower outlet in relation to kitchen sink? Height in approx meters?

 

[mwerty]

Shower outlet is almost directly above kitchen sink, 1 storey above.

 

[mwerty]

Thanks everyone for input - did some more testing and...

I think that it could be the shower head.. Measuring the rates has led me to determine:

10l/m directly from mixer.
10l/m from end of hose (without head on).
6.6l/m from shower head.

Cheap shower head! Can anyone recommend a shower head that will output 10l/m? It seems that none of them specify a rating for the flow rate?