Water pressure is being lost. Water is leaking back through the pump diaphram either because there is something in there or it has a hole.
Do you have a filter before the pump?
Cheers,
Peter
Look very closely for weeps or drips under the van, in all cupboards and tap connections. It only takes a slight weep to lose pump pressure momentarily.
Usual cause is John Guest connector or split in JG tubing.
Every 3-4 minutes indicates a weep.
__________________
Cheers, Richard (Dick0)
"Home is where the Den is parked, Designer Orchid Special 21' towed by Jeep Diesel Grand Cherokee Limited"
"4x250W solar panels, 360w solar blanket, Epever 80A charger and 4x135Ah Voltax Prismatic LiFePO4 Batteries".
You have a leak downstream of the pump. I had this exact problem for several years and could not find the leak, no matter how hard I tried. Only recently did I finally discover that it was a slow tap leak, but so slow that it took many hours for the drips to become apparent. If you can't find a leak, then replace the tap washers.
I'd agree with other comments that it's probably leaking somewhere in the water system. I had the same issue but the pump activated briefly only approx once every 30 mins. I had no noticeable water leaks, but I tightened every hose clamp & fitting where possible to do so and that fixed it. You could try plugging hoses in different parts of your water system to try to narrow down where the problem is.
