Toro 6‑Zone System: Zone 3 Runs Continuously, Zone 6 Won’t Start

Zone 3 stays on from pump start to pump stop, only closing when its flow‑control wheel is tightened manually. Zone 6 worked briefly after dewinterization but now fails entirely.

Diagnosis

Both symptoms point to valve internals:

• Zone 3: Diaphragm or solenoid not sealing – valve stays open.
• Zone 6: Solenoid or diaphragm failure – valve won’t open.

Test & Repair

1. Turn off water, remove each solenoid, activate the zone from the controller, and verify the plunger retracts. If not, replace the solenoid.
2. If solenoids test good, replace the diaphragms in both valves (see irrigationtutorials.com).