How to Replace a Lawn Irrigation Sprinkler Valve

Yard sprinkler
Dan Thornberg / EyeEm / Getty Images
  • 01 of 08

    Valve Replacement Basics

    A sprinkler valve
    Aaron Stickley

    Lawn and garden irrigation systems have valves that control water flow to the various zones in the overall sprinkler network. These valves are located near the origin point for the underground piping, near the water source. These valves wear out over time. Replacing a broken or leaking sprinkler valve in a home irrigation system is a common repair that can take less than an hour to complete. But before you start, it's important to examine the system carefully to confirm that the problem is due to a bad valve and not another cause. Common symptoms include leaks around the valve or at the sprinkler head farthest from the valve, inadequate water delivered to the sprinkler heads, or the sprinkler heads simply not coming on. 

    Perform some troubleshooting to make sure you have identified a bad valve as the problem before you replace it. 

    Continue to 2 of 8 below.
  • 02 of 08

    Gather Your Supplies

    Materials for sprinkler valve
    Aaron Stickley

    The most important part of this project is getting an exact replacement part for the sprinkler valve. Determine the type and size of the valve, or remove it and bring it to the store with you. As you select the new valve, make sure the PVC adapters fit the valve sockets before leaving the store. These adapters have a male threaded end to attach to the valve and a female slip-fit end designed to be solvent-glued to PVC irrigation pipe. Here are the essential supplies for sprinkler head replacement for most sprinkler systems: 

    • New sprinkler valve
    • PVC MIP adapters (two or more, as needed)
    • Plumber's tape
    • PVC primer and solvent glue
    • Smartphone or camera (optional)
    • Reciprocating saw, PVC pipe cutter, or hacksaw
    • Utility knife or sandpaper
    • Channel-type pliers
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  • 03 of 08

    Shut Off the Water

    Turning off the irrigation water supply
    Aaron Stickley

    Shut off the water to the irrigation system by rotating the valve handle on the main supply pipe of the system. The valve is closed when the handle is perpendicular to the pipe. If there is no shutoff valve for the irrigation system, you may have to shut off the water at the home's main shutoff or at the water meter.

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  • 04 of 08

    Disconnect the Wiring

    Disconnect valve wiring
    Aaron Stickley

    Note where the low-voltage wires are attached to the old sprinkler valve. This is important because you must connect the wires to the new valve in the same way. It's a good idea to arrange the wires so that each can be seen clearly, then take a photo of the wiring with a smart phone or digital camera. When you're ready, disconnect the wires from the sprinkler valve. 

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  • 05 of 08

    Remove the Old Valve

    Cutting away old sprinkler valve
    Aaron Stickley

    After making sure the water is off and wiring is disconnected, you can proceed to the actual replacement. 

    1. Cut through the PVC irrigation pipes just below the old PVC adapters, using a reciprocating saw, hacksaw, or PVC pipe cutter. Cut as closely as possible to the old fittings to conserve the maximum amount of pipe length. The new sprinkler valve will be only slightly lower than the old one.
    2. Remove all plastic burrs around the cut edges with a utility knife or sandpaper, being careful not to let the debris drop into the pipes. 

    Note: With the system shown here, the local code requires that the anti-siphon sprinkler valve must be at least 6 inches above the highest sprinkler head in the same zone, when the head is in the popped-up position. Check with your local building department for specific height requirements that apply to your project. If your valve will not be high enough to meet the code requirement, you may need to use couplings and some additional pipe to raise the sprinkler valve to a higher position.

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  • 06 of 08

    Prepare the New Valve

    Attach PVC adapters
    Aaron Stickley
    1. Install the new PVC male (MIP) adapters into the new sprinkler valve by wrapping plumber's tape around the threaded end of each adapter and threading it into a valve socket.
    2. Tighten all of the adapters with channel-type pliers, being careful not to over-tighten them, which can crack the plastic parts.
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  • 07 of 08

    Install the New Valve

    Applying glue to sprinkler pipes
    Aaron Stickley

    The new valve fits into the adapter you have just installed:

    1. Apply PVC primer and solvent glue to the insides of the female adapter sockets and on the outsides of the pipe ends, following the manufacturer's instructions.
    2. Fit the new valve onto the pipes, pushing down until the pipes fit fully into the adapter sockets.  
    3. Let the PVC solvent glue dry as directed by the manufacturer (usually about 30 minutes for full strength).

     

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  • 08 of 08

    Connect the Wiring and Test

    Completed sprinkler valves
    Aaron Stickley

    Follow these steps to finish the job:

    1. Connect the wires to the new valve in the same configuration that was used with the old valve.
    2. Turn the water back on by slowly rotating the shutoff valve's handle so it is parallel to the supply pipe. 
    3. Check the valve and all connections for leaks.
    4. Verify that you installed the wires correctly by making sure the timer works with the new valve.