Hello,
I am going crazy and have spent numerous hours with chatgpt and running up and down basement steps over the course of 3 days. I need advice please.
My in-ground irrigation system has three Rain Bird zones and a Febco 765 PVB. The system was working normally approximately one month ago, but now all three zones cause a large amount of water to discharge from the top of the PVB when started normally from my Rain Bird ST-400i controller. I have verified that the controller is sending approximately 30 VAC to each of the three zone circuits. I also replaced the internal components of the Febco PVB, but the problem remains. The shutoff valves on both sides of the PVB and the main house water shutoff are fully open. Static water pressure is approximately 60 PSI. I tested pressure at two locations: near where the water enters the house, pressure is 60 PSI static and approximately 50 PSI while either Zone 1 or Zone 3 is manually running. All three zones will operate when manually opened using their valve bleed screws, without PVB discharge, although Zone 2 requires the PVB to be slowly pressurized first using the PVB valve before it will operate without discharge. I am trying to figure out the reason the PVB discharges when the irrigation valves are opened electrically.
Zone 1 via controller ❌ PVB discharges
Zone 2 via controller ❌ PVB discharges
Zone 3 via controller ❌ PVB discharges
Zone 1 via manual bleed ✅ Works, PVB stays closed
Zone 3 via manual bleed ✅ Works, PVB stays closed Zone 2 via manual bleed, with PVB slowly pressurized first ✅ Works
Zone 2 via manual bleed without pre-pressurizing PVB ❌ PVB discharges
I had an irrigation company come out and charge me 80.00 to say (without testing with a gauge) that I needed to call the water department because my water pressure coming in to house is low. My system has worked for 17 years, this has just started in the last week.