How to Turn Your Sprinkler System Back on After Winterizing
A home sprinkler system makes it easy to maintain a healthy lawn, saving you time and effort compared to manual watering. However, if you turned off your system for the winter, there are important steps to follow before turning it back on in the spring. Skipping these steps could lead to leaks, broken pipes, or even damage to your home’s plumbing system.
This guide will walk you through the process of safely restarting your sprinkler system after winterizing it. By following these simple steps, you’ll avoid potential damage and ensure your system is ready for another season of keeping your lawn green and healthy.
Why It’s Important to Restart Your Sprinkler System Properly
Turning your sprinkler system back on isn’t just about getting water flowing again. If done incorrectly, you could create problems such as:
- Water hammer – A sudden rush of water that can damage pipes and valves.
- Leaks – If any part of your system was damaged during the winter, you might not notice it until it causes water waste or property damage.
- Low water pressure – If certain valves remain closed or pipes are blocked, your system may not operate efficiently.
- System inefficiency – Incorrectly adjusted sprinkler heads can lead to overwatering, underwatering, or wasted water spraying onto sidewalks and driveways.
Taking a few extra minutes to inspect your system before turning it on can save you from expensive repairs later.
What You’ll Need
Before you start, gather the following tools to make the process easier:
- Flat-head screwdriver – Used to adjust valves and test ports.
- Sprinkler valve key – Some systems require this tool to turn the water supply on.
- Pliers – Helpful for tightening loose fittings or removing debris.
- Pen and paper (or a phone app for notes) – To jot down any issues you notice during testing.
Steps to Turn Your Sprinkler System Back On After Winter
1. Locate the Main Shut-Off Valve
Your sprinkler system has a main water shut-off valve that controls the flow of water to the entire system. Depending on your home, this valve could be:
- Outside near the sprinkler control box.
- In a basement or crawlspace (for homes with indoor shut-off valves).
- Near the water meter if your sprinkler system is connected directly to your home’s plumbing.
Make sure you find the correct valve and avoid mistaking it for your home’s main water supply shut-off valve.
2. Find the Vacuum Breaker
A vacuum breaker (or backflow preventer) is a device that keeps sprinkler water from contaminating your drinking water. It is typically located:
- Above ground, near the house – Look for a copper or plastic assembly with two pipes.
- In a valve box underground – Some systems have the vacuum breaker housed in a protective box.
This component has two small shut-off valves and test ports that need to be adjusted before turning on your system.
3. Close the Vacuum Breaker Test Valves
Each pipe leading to the vacuum breaker has a small valve with a slot for a screwdriver. These are called test valves and are used to check for leaks and pressure issues.
- Using a flat-head screwdriver, turn each test valve until the slot is perpendicular to the pipe. This closes the valves and prevents leaks when you restart the system.
4. Open the Vacuum Breaker Shut-Off Valves
The vacuum breaker has two larger shut-off valves, one for each pipe.
- Slowly turn both handles until they are parallel to the pipes. This step allows water to begin flowing through the system when you open the main shut-off valve.
5. Reinstall the Main Valve Bleeder Cap (If Needed)
Some systems have a bleeder nipple on the main shut-off valve to release air pressure. If your system has this, check for a small metal cap and make sure it’s tightly secured before proceeding.
6. Slowly Open the Main Water Valve
This step is the most important because opening the valve too quickly can cause a water hammer, which can damage your pipes.
- If you have an outdoor ball valve – Turn the handle gradually until it is parallel to the pipe.
- If your shut-off valve is inside – You may need a sprinkler valve key to turn it counterclockwise slowly.
You should hear water filling the pipes. If you hear loud banging or sudden pressure surges, stop and slow down the process.
7. Test the Sprinkler System
Once the water is flowing, test your system zone by zone:
- Use the sprinkler control panel to run a manual test for a few minutes.
- Expect some air and sputtering at first—this is normal as air escapes from the pipes.
- Walk around and inspect each sprinkler head for leaks, clogs, or misalignment.
8. Check the Vacuum Breaker and Valves for Leaks
Go back to the vacuum breaker and shut-off valves to make sure:
- No water is dripping or spraying from connections.
- All shut-off valves remain in the correct position.
- The system is maintaining consistent pressure.
9. Adjust or Replace Sprinkler Heads (If Needed)
During testing, you might notice:
- Leaky or broken sprinkler heads – Replace damaged heads to prevent water waste.
- Misaligned spray patterns – Adjust the direction of sprinkler heads to avoid watering sidewalks or driveways.
- Clogged nozzles – Use a small needle or wire to clear out debris.
Taking time to make these small fixes will improve efficiency and prevent future problems.
10. Set the Timer for Automatic Watering
Once everything is working properly, program your sprinkler timer to match your lawn’s needs:
- Best watering times – Early morning or late evening to reduce evaporation.
- Frequency – Adjust based on local weather and seasonal rainfall.
- Zone settings – Ensure each area of your yard gets adequate coverage.
Final Tips for a Smooth Start
- Monitor your system for a few days – Look for leaks, pooling water, or dry spots.
- Check water pressure – If some zones aren’t working properly, pressure issues may need to be addressed.
- Schedule regular maintenance – Periodic inspections prevent costly repairs down the road.
Need Help with Your Sprinkler System?
If you’re unsure about turning your sprinkler system back on, or if you discover leaks, low pressure, or broken parts, it’s best to call a professional. At Liberty Plumbing Heating Air Conditioning, we have over 25 years of experience serving Murrieta, San Diego, and Winchester, CA.
Our team can diagnose issues, repair leaks, and optimize your system to keep your lawn looking its best. Whether it’s sprinkler system repairs, plumbing maintenance, or HVAC services, we’re here to help. Call us today at (951) 760-4215 to schedule an inspection and ensure your sprinkler system is ready for spring!
