Sprinkler and Drip System Not Activating: Master Valve or Main Supply Issue

Timer Runs but No Water; Valves Don't Work Manually

If the controller shows activity but no zone operates—even manually at the valve—the water supply is likely blocked upstream.

Main irrigation shut‑off valve – Ensure it’s fully open.
Master valve / Pump start relay – In the controller, look for a wire on the "MV" or "PS" terminal. If present, locate that master valve (usually just downstream of the backflow preventer) and verify it opens. A failed master valve solenoid or diaphragm will starve all zones.

Repair or replace the master valve components as needed.

Irrigation: Reducing Excessive Pressure in a Drip Irrigation System: Install a Pressure Regulator; Flooded Valve Boxes After Rain: Waterproof Wire Connections to Protect Controller; Shutting Off Water to Abandoned Hillside Sprinkler System; Starting a Lawn Genie System: Find the Main Valve and Backflow; Toro Zone 4 Runs Constantly: Manual Valve Operation Guide; Drip Zone Pressure Drop on One Branch: Finding Hidden Restriction; Two Zones Inoperative After Winter: Common Causes and Fixes; Leaky Zone After Two Valve Replacements: Flush Debris from Lowest Valve; Sprinkler System Water Hammer: Cracked Valve Top, Loud Bang; Constant Seepage from One Sprinkler Head: Valve or Drainage?

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