I recently moved countries to go and live in Croatia and be "off-the-grid" for most of the things, so one thing that my new house came with is a 12m deep well with a surface well pump: a Pedrollo Hydrofresh 24 CL, which comes with the Pedrollo JCRm 15M pump and the Pedrollo PSG-1 pressure switch.

So my wife and I went on a 1.5 month holiday and came back to a pump that fluctuates water pressure immensely. It goes up to 5PSI and immediately drops below 2.5PSI only to be filled up again to 5 PSI and do it all over again. I have checked the pressure switch and that seems to be working correctly as I was able to increase the water pressure to while no water is running to 3PSI again and even the cut-off to 5PSI. But nothing I have tried has fixed the issue of this pressure going up and down so quickly.

What am I missing? What should I try? I have no experience with these kind of things whatsoever and was unable to find any information that has this exact issue and how to fix it. As I live in rural Croatia it is very hard to find people that speak English or find someone knowledgeable enough to explain to me what I need to do.