pressure

[wanttolearn]

I went to my mates the other day as the bath tap whilst on full flow the pressure wasn't very good. Took bath panel off to check isolaters they were open fully. Notices the pipework was all in 15mm and not 22mm coming straight up from the combi boiler.
I mentioned this to him but I think it is the wrong tap as I think it's for a low pressure system as the rest of the house the pressure is great
Pic of bath tap

 

[Scott_D]

How many litres per minute are we talking?
What kW combi?

 

[gassafe]

The hot water supply always looks rubbish on these types of taps if from a combi as the 8 lpm looks like a dribble out of the big spout. Without a lpm reading from the tap it's difficult to comment