How to Repair a Sprinkler System

By Amanda Lutz Updated October 24, 2024

If you notice thinning grass, standing water, yellow patches on your lawn, broken sprinkler heads, or sudden hikes in your water bill, there may be an issue with your home’s sprinkler system. Because sprinkler systems are installed underground, it’s hard to know where or why your sprinkler system is malfunctioning. In this guide, we’ll explain how to troubleshoot problems with your sprinkler system and how to clean and repair different parts.

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When to Repair Your Sprinkler System

Homeowners should clean their lawn sprinkler system at least twice a year, especially if you live in an area with hard water. These cleaning cycles are a great opportunity to perform preventive maintenance and inspect the sprinklers to catch problems early.

However, sprinkler problems can pop up unexpectedly, so it’s important to stay vigilant for unusual behavior or problems with your landscape. Here are some of the most common indications that it’s time to repair your sprinkler system:

• High water bills: If your water bill is higher than usual, this may indicate an issue with your home’s plumbing or irrigation system. Look for marshy patches of grass and use the location to determine whether your sprinkler system or your house pipes are leaking water.
• Uneven watering: You can detect uneven water by observing the spray from your sprinkler heads. If one is sputtering as you water your lawn or not reaching as far as it used to, there may be an issue with the system. Another sign of uneven watering can also present itself as patches of underwatered, dry grass.
• Visible sprinkler damage: If there are broken parts on your sprinkler heads, your sprinkler heads won’t retract at the end of a watering cycle, or if you see cracks in unearthed irrigation pipes, it’s time for repairs.

Routine sprinkler maintenance can help catch many of the underlying problems. However, if seasonal cleanings and winterization tasks have slipped your mind, we recommend calling a trusted lawn care service that can inspect, clean, and repair your lawn sprinkler system.

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Preparing for Repairs

Homeowners can often manage their own do-it-yourself (DIY) sprinkler repair projects. Repairing sprinkler heads, addressing leaks, and replacing electrical components are all tasks you can do with some preparation and know-how.

Gather Materials

You’ll need different tools depending on the repair job at hand. Most supplies required to repair, replace, and clean other parts of your system will be available at your local home improvement store. Here are some common materials for different sprinkler repair projects:

• Mild soap for cleaning sprinkler components
• Rags, cloths, or an old toothbrush for cleaning sprinkler components
• Replacement parts, such as sprinkler heads, solenoids, or transformers
• Parts for leaky pipe repair:
  • Couplings
  • Hand shovel
  • Pipe cutters 
  • PVC glue
  • Replacement lengths of pipe
• Multimeter for diagnosing electrical issues

Take Safety Precautions

Modern sprinkler systems use water and electricity, so take appropriate safety measures to ensure your electrical components aren’t exposed to water. We recommend turning off the localized water supply for your sprinklers when repairing or replacing the system.

If you need to dig up parts of your sprinkler system, call 811, the national call-before-you-dig phone number. This service will send a technician to mark underground utilities on your property so you don’t dig up or damage electrical lines, pipes, or gas connections.

Once you’ve identified the specific problem that you need to fix, gathered your materials, and followed the above safety steps, you’re ready to begin your DIY sprinkler repair project.

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Cleaning Sprinkler Heads

Sprinkler heads will clog over time due to organic debris such as dirt and mulch or hard water mineral buildup. Fortunately, it’s easy to spot when your sprinkler heads need to be cleaned. Water won’t come out of the sprinkler heads properly, either dripping out in a slow stream or not coming out at all. You might also see visible clogs. We recommend cleaning your sprinkler heads at least twice a year—once in late fall and once in late spring.

Follow these steps to clean your sprinkler heads:

1. Prepare your cleaner: For dirt-based clogs, use a soapy water combination with one part mild dish detergent and one part water. If you see mineral buildup, mix a solution of one part calcium or lime remover with water.
2. Apply the cleaning solution: Use a soft cloth to remove mild obstructions and clean the clogged sprinkler head. For stuck-on or hard clogs, use an old toothbrush to scrub away any buildup.
3. Rinse and test the sprinkler heads: Rinse away the cleaning solution so it doesn’t touch your plants or get sprayed onto your lawn. Then, run your irrigation system to make sure the sprinkler heads work like they should.

If it’s been a long time since you last cleaned your sprinkler heads, walk around your lawn to spot-clean or deep-clean each one.

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Replacing a Sprinkler Head

Sprinkler heads can develop cracks and wear over time. Physical damage from lawn mowers, excessive mineral or spiderweb buildup, and cracks from improper winterization can break your sprinkler heads beyond repair.

Follow these simple steps to uninstall and replace your sprinkler heads:

1. Buy the right type of sprinkler head: You don’t have to replace your sprinkler head with the exact brand and model you had originally, but you do need to pick a replacement part that’s either pop-up (stationary, gear-driven, or rotor-driven) or impact, based on your current system.
2. Remove the broken sprinkler head: Turn off the localized water supply and clear the dirt away from your sprinkler head until you can see the vertical pipe riser below the head. Unscrew the old head while leaving the riser in place.
3. Install the new part: Wind PTFE thread seal tape around the riser threads. Then, screw in the new sprinkler head by rotating it against the threaded riser.
4. Test the new sprinkler head: Once the new sprinkler head is in place, test the sprinkler and replace any dirt and sod around the system.

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Repairing Low Water Pressure

Low water pressure can be caused by the sprinkler head coming loose and needing to be screwed back into place. Alternatively, the sprinkler head may have a clog and need a quick cleaning. Check the sprinkler heads for these problems before calling a professional to address low water pressure.

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Repairing Sprinkler Leaks

Sprinkler leaks can spring up from the sprinkler head or a broken pipe underground. You can determine the exact cause by tracing the water back to its source. For example, you may need to replace the sprinkler head if it’s dripping even when the sprinklers are off. If water seems like it’s coming up from under the grass, you have a damaged irrigation pipe that needs repairing.

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Repairing Damaged Pipes

Repairing damaged sprinkler pipes is a moderately difficult DIY project. If you’re uncomfortable completing the project, call an irrigation repair service to handle the job. However, if you want to take on the project yourself, follow these steps:

1. Address underground utility lines: Call your local 811 service to mark any underground utilities before you start.
2. Expose the broken pipe: Carefully dig away the soil around the pipe without damaging it.
3. Remove the broken section of the pipe: Turn off the water, and identify the full length of the broken pipe. Use PVC cutters to cut out the broken portion.
4. Install the new pipe: If you’re using a telescopic pipe, shorten and extend the pipe by twisting the couplings. Shorten the pipe to position it between the cut ends of the irrigation pipe, and untwist the couplings to lengthen the pipe and lock it in place.
5. Test the pipes: Turn the water back on and look for any signs of a leak. If you were successful with the job, you can replace the dirt and sod around the pipe.

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Diagnosing System Voltage Issues

Smart, automated sprinkler systems have electrical components that can fail over time. If your system is refusing to turn on or isn’t operating properly, test the system voltage with this quick process:

1. Locate and open the controller box.
2. Tighten any loose wires and make sure the battery is in place.
3. Test all the different sprinkler stations in your system. If one doesn’t turn on, it may have a voltage issue. Use a multimeter to measure the voltage by placing one lead tip against the common wire screw and the other against the screw holding the wire for the nonfunctional zone. The multimeter should display a voltage between 22V and 28V.
4. If the voltage is normal, check the ohms with your multimeter; they should fall within 20 to 60 ohms. High ohms indicate a poor electrical connection, low ohms indicate a bad sprinkler solenoid.

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Replacing a Sprinkler Solenoid

When your multimeter reads low ohms between the common wire screw and a particular zone in your sprinkler controller box, your sprinkler solenoid needs to be replaced. A sprinkler’s solenoid may also be bad if the sprinkler valve doesn’t open or the valve is hot to the touch. Here’s how to replace a sprinkler solenoid:

1. Turn off the water: Turn off the water and open the valve box.
2. Remove the old solenoid: The solenoid is connected by a wire and wire nut. Cut away the main wire (while cutting off as little as possible), and remove the old solenoid.
3. Replace the solenoid: Once the broken solenoid is out of the valve box, screw the new solenoid into place and attach the new wire to the main wire with a wire nut.

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When to Call a Professional

Homeowners comfortable repairing their sprinkler systems can make basic repairs or replace small parts. However, if your lawn irrigation system has significant damage or you’re not comfortable making your own repairs, make an appointment with an irrigation service. We recommend calling in a professional repair specialist in the following scenarios:

• There are large leaks or sections of damaged pipes within your sprinkler system.
• You can’t easily diagnose or troubleshoot the problem.
• You want a professional irrigation specialist to inspect, clean, or winterize the entire system.

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Our Recommendation

While regular maintenance can minimize the risk of broken sprinkler systems, some issues may arise unexpectedly. If you have a broken sprinkler head, leaking pipe, or defective solenoid, you can try to make those sprinkler system repairs yourself. However, if you can’t diagnose the sprinkler issue or are having difficulty repairing the system yourself, consider calling a professional sprinkler repair service.

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Sprinkler Repair FAQ