I have a sprinkler sys. with 4 zones. It loses all pressure when switching zones.I can manually pressurize tank and it will run thru cycle but it drops to 0 when it goes to next zone. I have put in new pressure tank,timer, pressure switch and pump with new pvc. Still not working. Any suggestions

  • you indicate you have a well system, not city water. Is the well pump continuously refilling the pressure tank to keep the pressure?
    – Traveler
    May 23, 2023 at 2:39
  • 1
    What is it supposed to do, stay pressurized at all times or only when there is call for irrigation? When you start the first zone does it pressurize? If you change the program to skip the first zone does the (now first) second zone pressurize? While irrigating a problem zone and after you manually pressurize it, does it run periodically to maintain pressure in that zone? Does it dump all pressure immediately after finishing the fourth zone?
    – jay613
    May 23, 2023 at 3:23
  • The well is dedicated only for the sprinkler system. It is supposed to stay pressurized at all times. I can skip to any of the four zones and it will operate for the scheduled time. It loses all pressure when advances to the next zone. It will stay pressurized after the last zone. The following day zone one will operate until zone two tries to kick in. It only drops pressure when advancing to the next zone
    – Roger
    May 23, 2023 at 13:05
  • The pump seems to be running continuously during timer cycle
    – Roger
    May 23, 2023 at 13:15
  • 1) If the pump runs continuously during irrigation and is solely for irrigation I wonder if the pressure tank is either too small or redundant or faulty? 2) Is there any electronic signal between the zone controller and the pump controller? If it's meant to be pressurized at all times, there does not need to be, but if there is I would look there. If there isn't, maybe the zone-switching is triggering an overpressure cutoff in the pump and your manual cycle is resetting or bypassing that?
    – jay613
    May 23, 2023 at 13:22

1 Answer 1


If the system uses individually controlled solenoid valves, one per zone, perhaps make sure that the next zone starts 1-5 minutes after the first zone stops, so there's no chance of overlap.

Overlap being both zones open at once; which could cause excessive flow and trip a low-pressure cutoff on the pump. Sprinkler solenoid valves do not work "instantly" since they do weird tricks with water pressure to use very little power for changing states.

  • I'm not too certain about potential similar failure modes with the other common approach I know of, the rotating distributor valves, but they seem less common these days - more of a holdover or suitable for special situations where there's a long run with no wires in place between the controller and where you want to "distribute" - plus, I doubt the described "I can pick any one of the 4 zones" applies easily, since they are (from the controller) one zone that gets switched off, then on, and rotates each time without the electronics knowing.
    – Ecnerwal
    May 23, 2023 at 16:20
  • I have sequenced my zones so they are 20 minutes between start times. I'll let you know if that solved the problem. They do have individually controlled solenoid valves.
    – Roger
    May 23, 2023 at 23:53
  • Best guess I have that fits the details of your description, but the proof is in the trying it!
    – Ecnerwal
    May 24, 2023 at 0:03

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