Zone 4 Runs Continuously: Valve Sticking or Misadjusted

Manual cycle test: zones 1, 2, 4, 5. Zone 4 kept running even when switching back to zone 1 or turning controller off. Only stopped by closing the main water valve.

Immediate Fix: Adjust Flow Control

1. On the zone 4 valve, turn the flow control stem fully open.
2. Close fully, counting turns.
3. Reopen to half the counted turns.

If Adjustment Fails: Clean Valve

• Remove valve bonnet screws.
• Inspect diaphragm for tears, debris, or deformation.
• Clean all ports (holes) in the valve body and bonnet.
• Reassemble carefully; keep parts clean.

A sticking diaphragm or obstructed exhaust port prevents the valve from closing when the solenoid de-energizes.