Just shows that system faults can sometimes have the daftest causes. Recently the flow rate while working has plummeted very quickly. So I assumed that the leisure battery was knackered and/or the split relay had gone kaputt. Tried all the usual stuff like swapping over the hoselocks, looking for hose kinks, lifting feed hose from tank to see if the gauze was blocked, replacing fuses even if they looked OK. Even tried running the engine while working to boost it. Wondered if the pump was on the way out when a brand new leisdure battery didn't fix it. And then I discovered what was wrong. A couple of years back, I replaced the final inlet/outlet to and from the pump. I went from barbed screw fitting that were jubilee clipped to john guest fittings. I did this for easy release of the pump to bring it in on the coldest nights. I removed the fitting from the outlet to see how well the pump was working and it gushed out. Pushed the fitting back a bit harder and everything ran beautifully. Fortunately, I never thropw bits and bobs away while still fault finding. So now I have a load of extra spare fittings and a battery
