First, stop the water
Turn the controller to Off. If the water stops within a minute or so, the valve is fine and the controller was telling it to run. If the water keeps running with the controller off, the valve itself isn’t closing.
To stop it right away, close the shutoff valve for the irrigation system. Many homes have one near the backflow preventer or the main line to the valves. If you can’t find it, close the main water shutoff to the house.
If the controller is the cause
Look for a program that was left in a manual run, more than one start time on the same program, or two programs that overlap. A controller that’s failing can also keep a station on. Check the display while the zone runs: if it shows that station as active, the problem is on the controller side.
If the valve is stuck open
Each valve has a diaphragm that seals against the valve seat, and a small solenoid on top that lets it open and close. The most common reasons a valve won’t close are:
- Debris caught under the diaphragm, often after a line repair or when the water is dirty.
- A worn or torn diaphragm that can’t seal anymore.
- The manual bleed left open. Many valves have a bleed screw or a solenoid you turn a quarter turn to run the zone by hand. If it was left open, the zone keeps running. Turn it back closed, hand-tight only.
- A stuck or failing solenoid, or a plugged bleed port.
- The flow control on top of some valves turned all the way down, which can stop a valve from closing properly.
Rebuilding a valve means opening it under the valve box lid with the water off. If the body is cracked, the valve is buried, or parts aren’t available, it gets replaced.
Water at a low head after the zone shuts off
If one head at the lowest spot keeps dribbling for a few minutes after the zone stops, that’s often water draining out of the pipe, not a stuck valve. A check valve at that head usually fixes it. If water seeps there constantly, the valve upstream is probably weeping.
When to call us
Call if the zone won’t stop with the controller off, the valve box keeps filling with water, a valve hums but won’t open or close, or you’d rather not open a valve yourself. We repair and replace valves, wiring, and splices across Fresno, Clovis, and the rest of our service area. See valve repair & replacement for what the visit includes.
Safety first: if you can’t stop the water, close the shutoff valve for the irrigation system, or the main shutoff to the house. Before you dig anywhere, call 811 to have buried utility lines marked.
Written by ACRE Landscape Co., Fresno & Clovis. Updated October 26, 2026.