You need to see what the reducing valve is actually supplying!
It does not seem to be supplying the shower based on that!
Tony
I think i mentioned in another thread that those taps are not the best for measuring the potential of the system.
The thread will be 1/4" bsp, so you'll need a 6-10bar 1/4" bottom entry pressure gauge
http://www.bes.co.uk/products/118.asp
Part no 12151
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