Sprinkler Valve Replacement in Solano, Napa & Sonoma County
A sprinkler valve fails in three set ways: it won’t open, won’t close, or leaks where it shouldn’t. Each has a part behind it. We find that part before anything is cut out, then fix it, or fit a new Rain Bird anti-siphon valve on waterproof wire connections and run it from the controller.
What’s inside a sprinkler valve?
A rubber diaphragm on a seat, a chamber of water above it and a small electric solenoid on the lid. Water presses on both sides of the diaphragm, but the top side is bigger, so the valve stays shut until the solenoid lets that top water out.
Power off. Water fills the top chamber, and the bigger area above holds the diaphragm down on its seat.
Power on. The plunger lifts, the top chamber drains to the zone, and line pressure lifts the diaphragm.
- A Solenoid
- Power from the controller lifts its plunger. A quarter turn by hand opens the valve.
- B Plunger
- A small spring-loaded pin sealing the top chamber’s exit. Stuck up, the valve runs on.
- C Bonnet
- The lid. The water under it is what holds the valve shut.
- D Diaphragm
- The rubber seal. Water reaches the top chamber through a filtered port in its center.
- E Seat
- The ring the diaphragm closes on. Pitted, it seeps, and the valve gets replaced.
- F Bleed screw
- Lets the top water out by hand, to run the zone or flush grit. Left open, the zone keeps running.
- G Flow control
- Limits how far the diaphragm lifts. Screwed right down, the zone won’t run.
- H Anti-siphon cap
- Keeps sprinkler water out of the house supply. It sits above the highest head on the zone.
A leaking valve can break the town’s rules
- Vallejo wants leaks stopped within 36 hours of finding them.
- Napa wants leaks of more than a gallon a minute fixed within 30 days of finding them.
- Windsor counts a leak left running too long as water waste.
Checked Sep 2026. Every provider’s rules: Watering rules by city
Diagram: a typical anti-siphon valve, simplified and not to scale.
Does a failing valve need replacing, or only a part?
A part, unless the seat is pitted or the body is cracked.
A new solenoid or diaphragm, or grit cleaned off the seat, fixes the rest. A pitted seat, a cracked body or a valve plumbed in backwards means a new valve. Your written estimate says which, and why.
What fails
The fix
A part
Cleaned out, diaphragm checked.
On the drawing: E Seat
The same valve diagram, simplified and not to scale.
| You see | What’s failed | The fix | Part or valve |
|---|---|---|---|
| Won’t shut off | Grit on the seat | Cleaned out, diaphragm checked | Part |
| Won’t shut off | Clogged filter under the diaphragm | Cleaned | Part |
| Won’t shut off | Plunger stuck up | Solenoid cleaned or replaced | Part |
| Won’t shut off | Hole in the diaphragm | New diaphragm | Part |
| Weeps at the lowest head | Worn plunger seal | Solenoid or plunger replaced | Part |
| Weeps at the lowest head | Pitted seat | New valve | Valve |
| Wet between runs | Bonnet joint, cap or fitting | Resealed; replaced if cracked | Part or valve |
| Clicks, but won’t come on | Flow control shut, or a blocked port | Opened; ports cleared, never drilled out | Part |
No power reaching the valve? That’s the wire or the controller: System diagnostic
When is it worth rebuilding the whole manifold?
When more than one valve on it is failing, or the pipe and wire around them are the weak part.
Valves on one manifold go in on the same day, so they age together. When one fails, Carlos quotes it both ways: that valve alone, or the manifold rebuilt once.
What a rebuild includes, as our own posts show it. Pick one, or tap a part of the drawing.
Set above the highest head they feed, so sprinkler water can’t run back into the house supply.
The supply side holds pressure all day, so it gets the heavier pipe.
An inline filter ahead of the drip zones, so grit stays out of the emitters.
Waterproof connectors on every solenoid splice, so a wet valve box can’t short the wire.
A patched old run is replaced, not taped again.
Each zone runs from the controller before the crew leaves.
Diagram: a typical three-valve manifold, simplified and not to scale.
3-year warranty on qualifying irrigation and lighting systems.
THE ROLLS-ROYCE OF IRRIGATION VALVES
…we strive to do all the simple things right and go the extra mile
Replaced my sprinkler valves, drip line timer, and drip line wiring
Luke Vera, Google review, Sep 2026 (opens in a new tab)
In Fairfield: Sprinkler repair in FairfieldOne zone out: One sprinkler zone not workingThe whole system: Irrigation
Valve quotes, and a click with no water
Quoted free, after Carlos sees the valves.
A new solenoid, one valve and a rebuilt manifold are different jobs, so we don’t post prices. Call, and Carlos looks at the valves first; the quote is free, in writing, and says whether a part or the whole valve is the fix.
The valve is getting power.
The click is the solenoid lifting its plunger, so the controller and wire are working. No water after it points to the valve or its supply: the flow control screwed down, a blocked port under the solenoid, or the water to the valves turned off.
The right fix for each valve.
Carlos finds the failed part before anything is cut out, and the quote is free.
Call for a free quote(707) 329-8391
