Hi Daz,
You asked a question on here about a month ago regarding the pressure build up in you system after you close the tap and how it blasts out when you reopen it again. Did you manage to sort your problem?
You suspected your flow controller, but I suggested that it could be you hose swelling.
I have had the same problem as you describe and put mine down to the hose swelling up which was also making the hose reel difficult to turn and pull the hose off of. Last week I ordered some replacement minibore hose from another supplier and put it on my existing hose reel and hose reel now operates perfectly. Unfortunately we are now back to the other problem of a bit of a delay sometimes when I open the tap.
Spruce