How to Fix a Sprinkler Leak

Sprinkler leaks can cost much money in wasted water, but you can fix many problems yourself. Start by locating the source of the leak—a valve box, head, or supply line. Then, take the necessary steps to fix or replace the leaking part.

Fixing a sprinkler leak isn’t overly complicated if you have the right supplies and tools. When you finish fixing the sprinkler leak, your system should work like new again!

Find Where the System is Leaking

The first step is figuring out where your sprinkler system is leaking. Sometimes, pinpointing where the sprinkler system needs fixing is the biggest challenge. It’s relatively easy to find the general area where water is leaking, but identifying the exact source of the problem proves to be a little more complicated.

Pro tip: Remember that leaks in the line can be hard to find unless they are significant. It may take digging up sections of your yard to find the problem.

Check the Valve Box

Start by locating the sprinkler valve boxes. They are buried in the ground and usually hidden underneath rigid plastic lids. In many cases, the valve boxes are close to the manifold that directs water from the main source to the individual valves.

Once you find the valve boxes, lift the lid off each one and check if the soil walls around the valves are wet.

  • If the soil is waterlogged, or there is standing water inside the box(es), the leak is occurring from one of the valves.
  • If the soil surrounding the boxes is dry, the leak occurs elsewhere in the system.

Observe Sprinkler Heads While Running

To see if the leak is at one of the sprinkler heads, having the system running while you’re investigating is helpful. Turn on a single zone (or head) at a time and carefully watch the water output.

Sometimes, it’s evident the sprinkler head is cracked (somewhere above ground) because you’ll see water pouring out of it instead of spraying like it usually should. If the leak is below ground, you may see an inconsistent, weakened spray.

When you notice a problematic head, mark it with a landscaping flag so you can find it once you turn the system and water off.

Watch for Standing Water in the Yard

If you couldn’t find a leak in the valve box or head, chances are that there’s a crack or split in the supply line somewhere. While running your sprinkler system, look at the direct lines between your sprinkler heads (this is likely where the underground supply lines are running) to see if there is any standing or pooling water on the ground. Flooding indicates an underground hose or pipe needs to be replaced.

Once you determine where water is pooling, mark off the perimeter of the standing water with landscaping flags so you know where to start digging.

Fixing a Leak In Your Sprinkler

Always remember to locate underground utilities before you do any digging and ensure the water source is turned on before you start doing any work.

Start by turning the system controller off to ensure the sprinklers don’t try to come on while you’re working. Then, find the main shut-off valve for the system—it’s usually by the water meter, a spigot, or close to where the outside water branches from the inside water source—and turn the handle to the off position so it’s perpendicular to the water pipe.

How to Fix a Valve

There are two scenarios for leaking valves in the valve box: a problem with the solenoid’s diaphragm or the entire solenoid needing replacement. The best way to tackle this is to look at the diaphragm first and see if it’s replaceable. If it isn’t, then replace the entire thing.

  1. Remove the screws securing the lid on the valve and set them in a small container (or put them in your pocket) for safekeeping. If there aren’t screws on the solenoid valve, you should be able to turn the entire thing clockwise to remove it.
  2. Pull the lid or valve off to access the rubber diaphragm.
  3. Take the diaphragm out of the valve and inspect it for any tears, rips, or holes. If there are noticeable issues, you can typically purchase a new diaphragm from an irrigation supply store or a local big-box retailer, depending upon the system manufacturer. If there aren’t noticeable issues, you may have problems with the valve and should replace the entire thing.
  4. Place the new diaphragm back in the valve and then put the lid back on top, tightening the screws or twisting the valve clockwise.
  5. Turn the water back on to check for leaks.

If there is still a leak within the valve box, the leaking valve needs to be replaced. You can hire a professional to do the repairs or follow online instructions to DIY.

How to Replace a Sprinkler Head

You’ll first need to dip up the leaking head and an area about ”6 to 12” surrounding it so you have plenty of room to work. Work slowly and carefully so you don’t damage the underground flex line or supply line with your shovel. When you get close to the head, use your hands or a small trowel to move dirt and mud away from it to expose the head and free it from the ground.

Replacing an Irrigreen Smart Sprinkler Head
  1. Pry the CableLock apart and disconnect the cable from the sprinkler head.
  2. Unscrew the old head from the flex hose in a counterclockwise direction.
  3. Thread the new sprinkler head onto the flex hose’s small end (without Teflon tape) until it is hand-tight. Do not use a wrench to tighten.
  4. Connect the cable to the replacement head, covering the connection with the CableLock previously used.
  5. Turn the water back on to check for leaks.
Replacing a non-Irrigreen Smart Sprinkler Head
  1. Turn the sprinkler head counterclockwise to remove it from the riser that connects it to the supply line.
  2. Check the riser for cracks. It needs replacing if the threads are worn or stripped, or the riser is cracked. Simply unscrew it from the line in a counterclockwise direction and attach a new one.
  3. Wrap the threads of the riser with Teflon tape and screw the new sprinkler head on in a clockwise direction. Hand-tighten until it is secure, then point it in the desired direction.
  4. Turn the water back on to check for leaks.

How to Replace a Section of Supply Line (Hose)

Carefully start digging in the area where you marked off where you suspect the system is leaking. Don’t forcefully jam the shovel into the ground because you don’t want to break the hose unintentionally.

Once you find the supply line in the ground, dig out 12 inches from each side horizontally and expose the broken section and about 6 inches of excess on both sides.

Replacing a Section of Flexible Hose

  1. Measure out and mark a guideline about 2 inches from each side of the leak, and use a pair of tin snips, a tubing cutter, or a pipe cutter to cut through the hose, removing the cracked piece.
  2. Use the piece you removed as a guide and cut a new flexible irrigation line the same size.
  3. Fit compression couplings onto both ends of the new hose section. Slide them about 1-2” onto the ends of the hose so they don’t slip or move around. If need be, wet the ends of the hose to make it easier to fit the couplings.
  4. Push the other end of each coupling onto the flexible line buried in the ground until the connection is tight.
  5. Turn the water back on to check for leaks.

Replacing or Repairing a Section of PVC Supply Line

PVC repairs are a little trickier than flexible hoses, especially if you’ve never worked with PVC pipes. How you approach the repair depends on the severity of the leak and the size of the section where the leak is located.

  • For major leaks, you can replace the entire length of the pipe or remove the broken piece and splice in a telescopic slip coupling. In both cases, you’ll need to use the appropriate primer and solvent to attach new pieces and allow at least 20 minutes of cure time after you’ve glued parts together before turning the water on.
  • For minor leaks, you can use silicone and rubber repair tape or repair epoxy to seal the leak. If you opt for either of these methods, carefully follow the manufacturer’s directions for using their product.

How to Replace a Flex Line

If you’ve found a problem in a flex line running to one of your Irrigreen heads, you’ll need to replace the line itself.

  1. After you’ve dug up the section of soil between the sprinkler head and the fitting or shut off where the flex line connects to the main supply line, unscrew the head in a counterclockwise direction. Do the same to remove the other end of the flex line from the PVC fitting or shut off valve.
  2. Take a new 12-inch flex hose and securely wrap the 1” end (the big side) with two or three layers of Teflon tape. Screw it clockwise into the PVC fitting or shut-off valve until it’s snug, and then tighten it to wrench-tight.
  3. Turn the water back on to remove dirt or debris from the flex line. Flush it for a minute or so and then shut the water off.
  4. Thread the sprinkler head back onto the small end of the flex hose (no Teflon tape needed) until it’s firmly hand-tightened. It doesn’t need to be tightened with a wrench.
  5. Turn the water back on to check for leaks.
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