You walk out in the morning and one section of the lawn is bone dry while the rest looks fine. Or the opposite: one zone keeps running long after the timer says it should be done, and there is water sheeting down the gutter.
Either way, it is almost never the whole system. In the calls we take across Fresno, Clovis and Kerman, a dead zone or a zone that won't shut off is usually one of four things: a timer setting, the valve, the solenoid on top of the valve, or the wire running back to the timer. You can narrow it down in about 15 minutes without digging anything up.
Step 1: Is it one zone, or all of them?
Go to the timer and run each zone manually, one at a time. The answer splits the problem in half.
| What you see | Most likely cause |
|---|---|
| No zone runs at all | Timer, rain sensor or rain delay, tripped outlet, or the water supply to the system is off |
| One zone never runs | That zone's settings, solenoid, valve or wire |
| One zone won't shut off | Debris or a torn diaphragm in that valve, or a bleed screw left open |
| One zone runs weak | A partly closed flow control, a broken line, or a clogged filter |
| Zones run at the wrong times | A second program (B or C) left on, or the clock reset after a power outage |
If nothing runs at all
Start with the boring stuff, because it is usually the boring stuff:
- Power. Many garage timers plug into a GFCI outlet that trips and never gets reset. If the display is blank, check the outlet and the breaker. Plug-in transformers also fail after years in a 110°F garage.
- Rain delay or rain sensor. After the first fall storm, a lot of timers are sitting on a rain delay someone set and forgot. Check the sensor switch too; if it's set to "active" and the sensor is stuck, nothing will run.
- Seasonal adjust at 0%. Smart controllers and many standard ones have a percentage slider. Turned all the way down, every zone gets zero minutes.
- Water supply. If a plumber worked on the house, or someone wrapped the backflow for a cold snap, the shutoff valve to the sprinklers may still be closed.
If one zone is dead
Check the program first
Look at the zone's run time in every program. It's common to find a zone set to 0 minutes, or set only in Program B while Program A is the one running. This happens a lot in the fall, when people start cutting run times back for the cooler weeks and the November 1 switch to the winter watering schedule.
Open the valve by hand
Find the valve box for that zone. In most Fresno and Clovis homes it's a green lid near the front hose bib, along a side yard, or buried under grass and mulch after years of growth. On newer builds in Kerman, the manifold is often right by the water meter or the side of the garage.
Most residential valves can be opened by hand in one of two ways:
- Turn the solenoid (the black cylinder with two wires) a quarter turn counterclockwise, or
- Loosen the small bleed screw on the valve cap.
If the zone comes on, the valve itself works and the problem is electrical: the solenoid, the wire, or the timer. Close it back up when you're done. If the zone does not come on, even opened by hand, the valve is stuck, the flow control handle on top is screwed all the way down, or there is no water reaching it.
Swap the solenoid
With the water off, unscrew the solenoid from the dead zone and trade it with the one from a zone that works. Turn the water back on and test both zones.
- The problem moved to the other zone: the solenoid is bad. It's a cheap part and usually the whole fix.
- The problem stayed put: the solenoid is fine. It's the wire, or something inside the valve.
Check the wire
Each zone has its own colored wire back to the timer, and all of them share one white "common" wire. Open the valve box and look at the splices. In our wet, alkaline clay, wire nuts that weren't waterproof corrode green and stop passing current. A shovel or an aerator can also cut a wire somewhere between the box and the house.
If you have a multimeter, test at the timer across that zone's terminal and the common terminal. Somewhere around 20 to 60 ohms is a healthy solenoid and wire. A reading with no continuity at all means the circuit is broken somewhere along the way. Very low resistance points to a short.
If the common wire is the problem, you'll usually see several zones die at once rather than one.
If one zone won't shut off
A zone that keeps running with the timer off is a valve problem, not a timer problem. The quick test: unplug the timer. If the zone still runs, it's the valve.
The usual causes:
- A bleed screw or solenoid left open after someone tested it by hand.
- Debris under the diaphragm. Grit, pipe shavings or a bit of rock gets stuck and holds the valve open. This is common right after a line repair.
- A torn or worn diaphragm. Our hard water is tough on rubber parts, and a 15-year-old valve is on borrowed time.
Shut the water to the sprinklers off at the backflow or the sprinkler shutoff until it's fixed. A zone that runs all night isn't just a big water bill. It's runoff, and in all three cities water running into the street is exactly what gets you a warning notice.
Zones that sat idle or ran short all summer often stick when the schedule changes. Gophers are active again in cooler soil and chew through wire. And the November 1 reprogramming for the winter schedule is when a lot of zones quietly get set to zero. If a zone died this month, check the program before you check anything else.
When to stop and call someone
The checks above are safe for anyone. Past that point, most homeowners are better off handing it over:
- Replacing a valve means cutting and gluing PVC in a muddy box, usually on a manifold with other valves crowded next to it.
- Tracing a broken wire underground without a wire tracer turns into digging trenches across the lawn.
- A zone that won't shut off and a leak you can't see often go together, and the water rarely surfaces where the pipe actually broke.
For reference, here's what these jobs usually run with us. The trip and the common parts are in the number:
| Job | Usually runs |
|---|---|
| Valve or wiring (a zone that won't turn on or won't shut off) | $190–$230 |
| Broken or leaking line | $180–$270 |
| Coverage and sprinkler heads | $145–$290 |
A straight valve or solenoid replacement is the low end of that first row. The high end is when the wiring back to the timer was never run right and has to be sorted out too. More detail on our sprinkler repair page, and seasonal upkeep in our sprinkler maintenance guide.
Send photos, get it fixed on the first visit
Two photos tell us most of what we need: the timer face and the valve box with the lid off. Add one of the dry or soggy area. We diagnose it from that, give you the price before anyone drives out, and bring the right parts so it gets fixed on the first visit.
Dead zone? Let's get it running.
Sprinkler repair in Fresno, Clovis and Kerman. Send photos, we price it, we fix it on the first visit.
Request sprinkler repair →Or call us at (559) 809-1230.
