Hi, I have just bought a bar mixer which I have tested and I get a really poor flow rate (a dribble) when on FULL hot and a good flow rate when on FULL cold. I am unsure if it is a problem with the mixer or the plumbing. I have mains CW and HW comes from the cylinder in the airing cupboard (same height as shower). I am unsure if the HW is pumped but there is a pump in the airing cupboard which comes on when I turn my gas boiler on to heat the water up. Is this a pumpred HW system or is the pump just circulating the HW to the boiler and back again? Anyway, the bar mixer is supposed to handle a 5:1 ratio imbalance. I measured the flow from CW & HW into a bucket. CW tooks 25 seconds and HW took 50 seconds to fill it. Does this suggest a 2:1 pressure ratio? How can I measure the BAR pressure? Thanks for any help. Sorry for all the questions.