At the risk of talking to myself here.
I found a drain off point just before the megaflo cylinder, which is on the cold water intake to the cylinder, to which I attached my pressure gauge. My stop cock is approx 3m to the right in the pitcure and the following components are fitted after the stopcock:
Stop Cock ->
22mm pipe to outside tap/kitchen sink ->
Water softener (high flow pipes. Tried bypassing, flow rate is unaffected) ->
Cold water isolation valve ->
3 bar Megaflo Pressure Reducing Valve ->
Balanced Cold ->
8 bar PRV ->
Speedfit reducing tee to ~3m of 15mm pipe to outside tap (shown in pic) ->
Drain off point (you can see the pressure gauge fitted)
This is reading as 2.6 bar. Sorry for the unclear pic below.
First question - is the gauge showing only 2.6 bar any cause for concern? Is it probably just inaccurate, or the Pressure Reducing Valve not able to produce 3 bar exactly, and perfectly normal?
Second more pertinent question. The 15mm outside tap after the Pressure Reducing Valve has less than half the flow rate (18 litres/min) compared to the 22mm (reducing to 15) outside tap which is connected before the Pressure Reducing Valve (has a flow of 40 litres/min). Can this be explained by the 15mm pipework? Could it be one of the other components inbetween causing this reduction in flow rate? Could it be a malfunctioning Pressure Reducing Valve causing a reduction in flow rate?
I'm tempted to just replace the Pressure Reducing Valve with the same model, but before I appoint a plumber and spend probably close to £120 doing this, I'd like to know if it's even a remote possibility.