Watts dual check valve failing in 4 years. What is a better replacement for a Watts LF7RU2?
I draw harvested rainwater from five 1500 gal. cisterns for irrigation only, including a system to switch to potable town water when the tanks are dry (see photos). In troubleshooting a leak losing 10 gal/hr only when the potable water valve is open (per town water utility reports), my irrig. pro and I have narrowed the problem to the 1" Watts LF7U2-2 dual check valve that should be keeping town water from flowing into the RWH tanks. The configuration worked for 9 years before these leaks started. Both dual check valves have been replaced; the 3/4" Watts LF7RU2-2 in 2024. Is there a better valve choice than the 1" Watts LF7U2-2? I should be able to leave the town water valve open at all time. A relay runs a pump in the RWH tanks; when there is no water in the tanks, irrigation should come from the potable water. Thanks.
