Locating the valves that control your lawn sprinkler irrigation system is an important part of maintaining and troubleshooting the system. The valves turn water flow on and off to different zones of the irrigation system and are usually installed out of sight underground. With some detective work, you can find the valves and gain access to make any necessary repairs or adjustments.

Understanding Irrigation Valves

Most lawn sprinkler systems are divided into zones, with each zone covering a specific area of the lawn. The valves open and close to allow water to flow to the sprinkler heads in each zone. There are a few types of valves that might be used:

Electric valves – These are activated by an electronic timer or controller and are the most common type used in residential systems today. The valve opens when power is sent to the solenoid and closes when power is cut off.
Manual valves – These are opened and closed manually using a bleed screw or handle on the valve body. They are less common but allow for manual control of each zone.
Pressure regulating valves – These help control water pressure and flow to prevent damage to lines or misting from heads. They may be installed on the main line or on individual zone lines.

Valves are usually 1 inch in size and made of plastic or metal. They will have pipes connecting on each side – the supply line bringing water in and the output line going to the zone sprinklers. Wires will also connect to electric valves to control activation. Understanding what valves look like and how they function will help immensely in locating them.

Locating the Irrigation Control Box

The first step in finding the valves is locating the main irrigation control box or timer:

Check along the side of the house, garage or where your main water pipes enter. Control boxes are often located close to the water source.
Look for a green plastic box 6-12 inches on each side mounted on the wall or a metal box on a pedestal. These house the wiring and allow access to the control timer.
Trace wires from the control box along the house or lawn to locate the general valve area. Wires are often buried 6-12 inches deep.
Use wire tracing tools if available to follow the path of the low voltage control wires going to valves.
Contact the irrigation system installer if possible to ask where valves were placed.
Refer to any landscape plans that may exist showing the irrigation layout.

Once you’ve found the approximate location for the valves, it’s time to start digging.

Digging to Access the Valves

Valves are buried 12-18 inches deep in average landscapes. PVC pipes will run to and from the valves:

Start digging near the control box or where you found buried wires.
Clear away sod and begin digging a hole approximately 18 inches around and 12 inches deep.
Expand your search outward in circles if valves aren’t found in the initial spot.
Use a long screwdriver or probe to poke into the soil and hit pipes to help locate them.
Carefully dig by hand around any pipes you find to follow them to the valves.
Use a garden hose to wash soil off pipes and valves as you uncover them.
Expand the hole as needed to fully access valves and connecting pipes.

Safety tip: Call 811 before digging to have utility lines marked to avoid hitting any gas or electric lines. Only hand dig carefully around pipes once found.

Identifying Valve Location and Order

Once you’ve uncovered the valves, determining which valve controls which zone is important:

Electric valves will have control wires screwed into ports on them. Trace these back to determine which zone they activate.
Turn on the irrigation system manually and watch to see which valve opens for each zone as it runs.
Label each valve with its zone – use tags or write it on the valve body. Document if necessary.
Draw a simple valve map to show the valve locations and corresponding zones if not readily apparent.
Number valves sequentially for easier reference. The first valve found may not be zone 1.

Taking the time to identify and mark valves makes working on the system much simpler down the road.

Accessing Valves in Valve Boxes

In some systems, valves may be installed in round plastic valve boxes:

Look for round green covers protruding from the ground along the irrigation pipe paths.
Remove the cover to access the valves inside. Covers usually lift off or unscrew.
Clear out any accumulated dirt and debris to access the valves.
Valve boxes are 12-18 inches deep to allow access to valves without excessive digging.
Extend boxes to grade with extensions if they have sunk too low over time.

Valve boxes are very convenient for making valve access quick and easy. Just pop the lid off to work on the valves when needed.

Modifying the Valve Box for Access

If valves are found buried without a box, consider installing access boxes:

Purchase 10-12 inch round valve boxes and extensions at irrigation supply stores.
Dig out the area around each valve, allowing 6 inches clearance on all sides.
Place a base with fine gravel for drainage at the bottom.
Set the valve box centered over the valve and level with grade.
Backfill around the box with soil, compacting as you go to stabilize it.
Add extensions as needed to raise the lid to surface level.
Replace the lid and sod or seed around the box.

While more work initially, boxes simplify maintenance and repairs down the road. They also protect valves from damage.

Testing Valves After Access

Once uncovered, valves should be tested:

Turn on the system and observe each valve to ensure it opens fully and closes completely.
Check for leaks around valves and pipes. Tighten fittings or replace components as needed.
Clean out any debris or corrosion from valves. Scrub with wire brush and spray with water.
Lubricate valves if sticking. Use silicone spray made for irrigation valves.
Inspect solenoids on electric valves and clean or replace if not activating properly.
Open bleed or flow adjustment screws to flush valves with water.

Taking the time to test valves ensures they are in proper working order after being buried. Catch any problems before returning valves underground.

Covering Valves After Testing

Once tested and any repairs made, valves need to be re-covered properly:

Fill any voids around valves and compact soil to stabilize.
Cover electric valves with gravel then sand. This allows drainage and protects wires.
Place a plastic sheet over valves to protect from soil. Secure in place.
Backfill hole with excavated soil. Mound 6-12 inches to allow for settling.
Pack soil down in layers using water to compact tightly.
Test zone to ensure valves still function properly before fully covering.
Replace sod or seed over the hole to restore the lawn surface.

Burying valves properly will maximize their lifespan. Avoid just throwing soil over valves haphazardly.

Troubleshooting Valve Problems

Issues found when testing valves may require some troubleshooting:

Valve leaking

Tighten valve fittings – hand tighten plus 1/4 turn. Don’t over-tighten.
Check for cracks in the valve body. Replace leaking valves.
Ensure rubber seal is in place around solenoid plunger on electric valves.

Valve not opening fully

Open flow control screw to remove debris restricting valve.
Check for wiring issues preventing electric valves from activating.
Replace old or damaged valve diaphragms preventing full opening.

Valve not closing fully

Adjust flow control screw clockwise to tighten close. Do not over-tighten.
Remove debris or mineral buildup preventing valve from closing completely.
Replace damaged diaphragm if valve continues to leak when off.

Valve sticking or not activating

Lubricate using spray valve lube or silicone spray if valve is sticking.
Clean out any debris or mineral deposits on valves.
Replace damaged diaphragm or solenoid.

Taking the time to uncover and maintain valves helps ensure a healthy irrigation system. Catching problems early prevents major issues down the road.

When to Call a Professional

In some cases, it is best to have a sprinkler pro take a look:

If you are unable to locate any of the irrigation valves.
For major leaks, broken pipes or valves that require replacement.
If wiring problems prevent electric valves from activating.
For major additions, repairs or modifications to the system.
For annual system inspections and tune-ups.

While regular maintenance is a DIY project, professionals have the tools and experience to tackle more complex irrigation issues. They can also modify and upgrade systems if needed.

Preventing Future Valve Problems

Regular maintenance helps avoid many valve problems:

Inspect valves at the start of each season when activating the system. Look for leaks or issues.
Open up boxes and flush valves annually with water to prevent buildup and sticking.
Have professionals perform annual system tune-ups to catch issues early.
Winterize the system properly to avoid damage from freezing.
Update older valves to new models for improved performance.
Repair damaged wires going to electric valves to ensure proper activation.

Investing some time into preventing valve problems will extend the life of your system and ensure it keeps performing as desired.

FAQs About Finding Irrigation Valves

Locating and accessing your irrigation valves in order to maintain or repair them is an important DIY sprinkler system skill. Here are answers to some frequently asked questions:

How many valves will I have?

Most residential systems have between 3 to 8 valves – one for each zone of the system. The number depends on the size of your landscape and how the system was designed. There is usually a valve for every 4-6 sprinkler heads.

Where should I start looking?

Begin your search near where the main water supply enters the house along with where your irrigation controller box is mounted on the wall. Valves are normally close to the water source and control wires.

How deep are valves buried?

On average, valves are buried 12-18 inches below the surface of the lawn. This allows access for maintenance but protects from damage. Tracing pipes from the valves is the best way to locate them.

What if I can’t find the valves?

If you are unable to locate any valves after extensive searching, your best bet is to call in a professional installer. They have tools to locate valves and wires and understand common placement locations.

Do valves require much maintenance?

Basic inspection and testing annually is recommended. Occasionally valves may need tuning up with lubrication, adjusting or debris removal. Replacing very old or damaged valves may be needed in some cases.

How do I know which valve is for each zone?

Activate each zone manually at the controller and observe which valve opens for that zone. Label the valves and create a valve map showing the zone layout. Numbering sequentially can also help identify zone order.

What if my valves are stuck shut?

Turn off water first, then carefully open the bleed or flow control screw on the valve a few turns to flush out any debris. Use spray lubricant made for irrigation valves. Turn water on slowly to see if valve opens.

Can I convert manual valves to automatic?

Yes, you can add actuators to manual valves to allow them to open remotely with wires from the controller. An irrigation pro can handle this. May also require upgrading the controller.

When should I seek professional help?

If valves can’t be located, major leaks or repairs are needed, replacement is required or the system needs redesigning or upgrading, it is best to call in a pro.

Knowing the answers to common valve questions will make your system maintenance much smoother. Locating, inspecting and repairing your valves periodically is essential to keep your sprinklers performing efficiently.

Conclusion

Being able to find and access the irrigation valves controlling each zone of your in-ground sprinkler system is crucial for proper maintenance and troubleshooting. A bit of detective work is required, but with some basic understanding of where valves are typically located and how they function, you can uncover them yourself.

Carefully tracing control wires and water pipes from the timer box is usually the best approach for locating buried valves. Digging exploratory holes and probing the soil makes finding valves much easier. Taking the time to label each valve makes system testing and repairs straightforward. Extend valve boxes to surface level if possible for quick access down the road.

Testing and servicing valves after uncovering them allows catching issues early before they become big problems. Periodically inspecting, cleaning and tuning up valves extends system lifespan and keeps your lawn hydrated with minimal hassles. Knowing when it’s best to call in a professional irrigation specialist is also important for major repairs or upgrades.

With a properly maintained irrigation system, your lawn will thrive for years to come. Keeping valves in top shape through regular access and care is the key to lasting performance.

How to Find Lawn Sprinkler Irrigation Valves