There is a lot to understand when it comes to the components of a sprinkler system. At Sprinkler Master Repair (Fresno, CA), we not only care to provide you with quality service, but we strive to teach quality service as well. A job is still half-complete if you didn’t learn something along the way, so today we are here to help you know all you need to know about automatic sprinkler valves, and what they do for your lawn! If you want to get in touch with Sprinkler Master Repair (Fresno, CA), simply give us a call, at (559) 422-3808.

The Automatic Sprinkler Valve Purpose

The purpose of an automatic sprinkler valve is to turn the water on or off to the sprinkler zones.

Names of Parts

  • A solenoid is a device that lifts a cylindrical metal bar up and down through electromagnetism. When this cylindrical bar raises, it allows water to flow through the valve. The majority are actuated with 24-volt ac electricity.
  • Valves also have bleeder screws that allow manual operation of the valve. The bleeder screw is small, and when it is unscrewed to allow air into the top of the valve, it then allows water to flow through the valve.
  • Another feature some valves have is called flow control. This is a small gate valve that when screwed clockwise restricts the flow of water, and when turned counterclockwise, allows water to flow again. A valve can be turned off all the way within the flow control.
  • On the inside of the valve, there is a rubber diaphragm and a spring that is used with the valve parts above to help control the water.

Common Brand NamesFresno CA Sprinkler Master Automatic Sprinkler Valves

Part Names

Casing: The plastic outside containing all of the internals.

Wiring: The electrical connections allowing the valve to function.

Diaphragms: The rubber piece inside that lifts or falls, allowing water to flow.

Solenoids: A metal rod that is lifted or dropped by electric flow allowing the diaphragm to move.

Flow Control Screw: Screw on the top of the housing that allows the pressure to flow through the valve without the solenoid being actuated.

How Automatic Sprinkler Valves Work

An automatic sprinkler valve is electronically controlled. A sprinkler timer tells the valve to open or close using 24v ac electricity, with the solenoid allowing the diaphragm to open, and water to flow through. Valves can also be turned on manually with the bleeder screw turning it a quarter turn counter-clockwise.

Pros and Cons

  • Automatic sprinkler valves can be turned on and off electronically or manually.
  • They can be battery powered.
  • There are many different brands and styles, but all use the same universal functions of having a diaphragm and a solenoid actuating them.
  • When there’s any electrical damage, valves will not turn on. This can include hard water residue build-up on solenoids.
  • Valves being stuck on are usually caused by torn Diaphragms, dirt or rocks ruining the valves, solenoids breaking off in the valve, and the flow control getting stuck in the closed position.

How to Diagnose Automatic Sprinkler Valves


  • If the valve does not turn on, it’s most likely an electrical issue.Fresno CA Automatic Sprinkler Valves
  • Start by turning on the clock for that zone, then feel the solenoid with your hand. If you feel a small vibration, the solenoid is on and functional. If so, check the flow control. Turn the flow control counterclockwise as much as you can. If the valve still does not turn on, unscrew the solenoid by turning counterclockwise.
  • If there is still no flow, use the bleeder screw. Manually turn on an adjacent valve to ensure that you’re getting water pressure. If the valve is installed backward, water will never flow through. At that point, if none of those work, replace the diaphragm and clean the valve out. If that still does not work you’ll need to replace the entire valve. Make sure there’s water pressure running to it.


  • If it’s an electrical issue and you’re not getting power, You need to do deductive reasoning to find out which of the three possible problems you’re dealing with. Those possible problems are; the solenoid is bad, the wiring is bad, Or, the timer is bad. We cover more detail on electrical later in the course.
  • If a valve is sticking on and is getting power, you will need to replace the valve or rebuild it.
  • To rebuild a valve, you will first need to unscrew the screws, take off the top, and take out the internals. Remember exactly how you took it apart. Replace all the internal parts, the solenoid, manifold, spring, and top of the valve, and screw the assembly together again. Remember if you replace any parts of any valve to match it with the exact same brand and model. If any parts are mismatched or improperly installed, it will probably not work.
  • To replace a diaphragm, take apart as shown in the video, and simply place the new diaphragm in place of the old one, and reassemble the valve.
  • To replace the solenoid, remove the wiring, unscrew from its housing, and screw the new one into place, and connect the wiring using waterproof wire nuts
  • If the valve is damaged or cracked it is best to replace the entire valve.

Tips and Tricks

Always try to use waterproof wire nuts on your electrical connections. They’ll hold up better in the long run. Also, the easiest way to see if the valve is getting electricity is to activate it via the timer and feeling if the solenoid vibrates. If it doesn’t, you need to check the wiring. If it does, there’s a problem with the valve internals.

As time passes and there are any other sprinkler issues you currently have — or think you may have down the road — don’t hesitate to give Sprinkler Master Repair (Fresno, CA) a call today, at (559) 422-3808. Our main goal is to provide the highest quality service at an affordable price, and that includes any issues with your automatic sprinkler valves. That is the Sprinkler Master Repair (Fresno, CA) difference. We install the best and repair the rest, every time!