I have just purchased a brand new v11 spring controller and shurflo pump with pressure switch but I am having problems . It won't auto calibrate as it comes up with p5 & error . I can calibrate it manually and the flow rate adjusts up & down ok but when it's on de I can hear my pump trying to start every 4 seconds which will probably use my battery if not switched off . I thought that once it was on de it shouldn't keep trying to start . I don't have any leaks anywhere and any ideas why it won't auto calibrate . I have changed my hose to different size as well but with no luck . Any help much appreciated as its doing my head in . I changed from a manual controller to a digital as was told they were a lot better and didn't leave pressure in your hose .