Lack of flow from shower

[pen]

I've installed a Bristan Artisan surface mounted dual control shower in my bathroom, and the flow is rather pathetic. The water supply is mains pressure, and it looks as if it's the shower control itself which is restricting the flow since the hand held spray on the bath mixer tap (also Bristan, but from their Quadrant range) in the same room gushes out most satisfactorily. I know some shower mixers come with removable restrictors and I did check for these before installation, but didn't find any. Bristan say that the shower is suitable for both gravity and mains systems, from 0.1 to 5 bar, so I would have thought there would be some sort of widget somewhere, but where? The irritating person on Bristan's helpline refused to give me any information unless I told her the water pressure, but as my all purpose girls' handy manometer isn't...err...to hand, it seems I am stuck. Does anyone have any knowledge of what Bristan might have concealed in this device?

Thanks.

Pen

[John Rumm]

IIRC, when I installed a Bristan shower (might have been the Artisan - bar type flow control on the left end, temp on the right), there were no adjustments required for mains pressure. Even if you were your would expect tham to add restrictions for a mains pressure system not remove them.

(Not a paricularly good shot of the mixer, but:

take it both your hot and cold feeds to the shower are mains pressure? (i.e. combi boiler or pressurised storage system etc).

What happens if you remove the shower head - how fast does the water come out of the pipe on its own?

Is is a multi mode head? If so have you tried rotating the control ring on the shower head?

If you are sure you have both mains hot and cold, and want to talk to the help line again, why not just say 3 - 4 bar and see what they tell you.

[Mike Halmarack]

As per suggestion made in an earlier thread, I went to Halfords today and bought a traditional tyre gauge. Using a polythene tube, some masking tape and a couple of jubilee clips I connected it to my bath's cold tap and found that the cold water pressure is 2.5 bar.

[pen]

handset and riser rail set with one from Grohe. I'm quite sure that I have mains pressure hot (Megaflo) and cold, and I've tried taking the hose and handset off completely to see what came out - which was, not as much as I'd like!

Good idea, I might try that tomorrow.

Pen

[pen]

Ooohh, I missed that one. I might even have an old tyre inflation foot pump in the attic somewhere that I could use......

Thanks, Pen

[John Rumm]

In which case it sounds like one of two things: either there is something wrong with the mixer (or its installation), or, your expectations of flow rate are a tad high!

It might be worth actually getting some figures for the flow rate. Could you time how long it takes to fill a bucket of known size? That should let you work out how many litres per min it delivers. Once you know that it is much easier to see what is happening.

If you can also say to them "I have measured it and I am only getting 3 lpm from it" then it is far more obvious there is a problem.

(if however you are getting 10+ lpm then it might be an expectation problem - many shower mixers that are designed to run from mains pressure hot water will be designed to limit the flow to what can be reasonbly expected from a small combi boiler)

Another thought: did you fit isolator valves in the shower pipework? If so have you checked they are fully open? Also did you use "full bore" valves rather than the normal smaller bore service valves? If not, and flow is marginal, changing the valves may help.