Ok guys -  looking for some help/advise on whats happening with me system....
In Feb I noticed the battery life was not as good as it had been – I put this down to the cold weather as was going to get a new one – when I checked the batt, the fluid was low so topped it upand tested it all OK  and things seemed to improve,  but this last week I am barely getting 45 mins out of it before the pump starts to cut out.
If I start the van up all is OK – but this is now using diesel,  Yesterday after the leisure batt died (110A -  large size) I used the van batt without running the engine – this also lasted about 40 mins – then I needed a jump start. 
 Today I ran the engine while cleaning for 15 min periods just to keep things going, but the flow rate was pathetic – I could pee quicker and needed to turn the dial right up as per photo to get a decent squirt of water. 
SO WHY IS THE SYSTEM USING SO MUCH POWER ?
I have noticed that the flow varies from day to day – some days its gentle and others the water really fizzes out.
If I turn the flow off using an in line tap the pump will cut out, but usually it will blow off a pipe or connector.
Thanks  Darran