Protect Your Sprinkler System from Freezing Pipe this Winter

As the winter season approaches, it is crucial to take proactive measures to protect your sprinkler system from freezing pipes. Freezing temperatures can cause significant damage to the pipes and components of your irrigation system, leading to costly repairs and potential disruptions to the water supply.

In this article, we will discuss the necessary steps to winterize your sprinkler system, common issues related to frozen pipes, and essential tips for protecting your system in freezing temperatures.

Why is winterizing important?

It’s crucial to properly winterize your sprinkler system to prevent potentially serious and costly damage from freezing temperatures. Frozen pipes can rupture or burst under pressure as water expands during the freezing process.

This may lead to flooded landscapes as thawed ground sinks from shifted soil. Winterizing your sprinkler system before the first frost helps avoid repair bills that can easily cost hundreds of dollars, if not more.

The simple process takes only an hour or two but provides peace of mind until spring.

When should I winterize a sprinkler system?

Most experts recommend beginning the winterization process once overnight lows consistently reach freezing in your area. To determine when that will be, check local weather forecasts and historically reported first frost dates.

As a general guideline, aim to finish winterizing your sprinkler system by late October to mid-November across most of the US. Systems in colder northern regions may need protection even earlier once daytime highs struggle to rise above freezing.

Play it safe by finishing before any expected cold snaps to fully protect your pipes and sprinklers from harm over the winter.

Turn Off Your Outdoor Water Source and Drain Sprinkler Pipes

The first crucial step is to turn off the outdoor water supply to your sprinkler system. This is usually accomplished by closing the appropriate exterior faucet or spigot, commonly called a hose bib. Make sure to turn it fully to the off position.
Once the water source is shut off, you can begin draining residual water from all pipes, valves, and sprinkler heads. Start by opening the drain valve located at the lowest point of the mainline piping, which is often near the backflow preventer or control valves.

This allows gravity to drain water from the entire system. It’s a good idea to have several 5-gallon buckets on hand to catch draining water as you release it from other parts of the system as well.

Open drain ports on valves one at a time, directing flow into buckets. You may need to use a screwdriver or similar tool to open stubborn drain valves that have not been used in a while.
For above-ground systems, also open drain ports on sprinkler risers. This fully evacuates any trapped water inside vertical pipes.

Pay extra attention to draining zones located furthest from the drain valve. These zones tend to hold more residual water. It is difficult to remove this water through natural drainage alone.

Blow Out Sprinkler Lines with Compressed Air

Now that your pipes are drained, it’s time to use compressed air to clear any remaining water from the sprinkler lines. A standard blowout is performed using an air compressor attached to the system with a blowout plug.

Air compressors suitable for this task should provide at least 100 PSI of pressure. You’ll also need a blow-out plug. Screw it into the threaded inlet of your piping system.

The threaded inlet is usually near the backflow preventer. The plug houses a tapered tip that allows compressed air to be released into the pipes once hooked up to the compressor.

Begin with the zone valve closed that corresponds to the first zone in your line. Attach the air compressor to the blowout plug and slowly release compressed air.

You may see bursts of water spraying out of sprinkler heads. The water is gradually replaced by only air as the system forces it out.

Move zone by zone, repeating the process of closing the valve, blasting air pressure through the lines, and opening sprinkler heads to clear clogs. Blow air for a full minute per zone at minimum.

Watch for any sprinklers that fail to discharge fully, indicating a clogged orifice that may require cleaning.

It’s important not to exceed your system’s maximum rated PSI, usually around 100. Using too much air pressure can damage sprinkler heads, pop-up rotors, or pipes.

However, a thorough blowout is critical to preventing frozen sprinkler pipes this winter. It removes every last drop of moisture from inside the piping.

Flushing with Antifreeze Solution

For an extra layer of protection, flush the piping with a non-toxic antifreeze. Use a propylene glycol-based antifreeze made for sprinkler winterization.

These antifreezes have corrosion inhibitors and prevent lines from freezing down to -50°F.

Start by connecting a container of premixed antifreeze to the sprinkler inlet. Open downstream drains and run each zone.

This allows the antifreeze to flow through and coat the insides of pipes and sprinkler components. Once complete, disconnect sprinkler heads and drain excess solution before storage.

Disconnecting and Storing Sprinkler Heads

With the system drained and flushed, it’s time to remove sprinkler heads and protect them from damage over the winter. Begin by turning off water to individual zones and relieving pressure if needed.

Then use a socket wrench or tool to disconnect the heads by turning the central screw or nut counter-clockwise. Store pop-up sprinklers in the retracted, down position.

Keep heads and other small parts, such as nozzles, organized together in Ziploc bags. Label them by zone for easy reinstallation next spring. Larger rotor sprinkler bodies can be bagged individually.

Place all sprinkler storage containers in a dry, insulated location free from the chance of freezing, such as a garage. This protects plastic and rubber parts that can become brittle in the cold.

Insulating Pipes and Valves Prone to Freezing

Check for exposed pipes situated exterior to buildings, like at the house connection point or zone valves near outer walls. These need insulation to guard against freezing in direct contact with the winter elements.

Use foam pipe insulation sleeves secured with plastic zip ties. As an extra layer, apply heat tape specifically rated for winterization and marked for burial use to give overloaded protection.

Storing the system properly after drainage and flushing ensures its safe reactivation when temperatures warm up again. With some preparation, your sprinkler investment can withstand winter’s hard frost safely.

Winterizing the Irrigation Controller

Most modern smart controllers have built-in protection against freezing temperatures. It’s still best to winterize the unit itself.

Locate your controller, then disconnect its power source. This could be a standard electrical outlet or batteries. Remove any batteries from battery-powered controllers and store them properly to avoid leakage issues over time.

For wall-mounted controllers, consider removing the entire unit from the exterior enclosure. Bring it indoors during the winter months.

This shields critical electronics from potential moisture damage. The box is not completely sealed from the elements. Leave detailed reinstallation instructions and maps for stepping through the process come spring startup.

As an alternative to removal, consider applying a silicone-based lubricant to exposed metal and moving parts like toggle switches before sealing the enclosure.

This prevents corrosion from accumulated condensation that can freeze internally. Apply a bead of clear caulk around the seams of any outdoor enclosures for an extra weatherproofing layer as a precaution.

Properly protecting your controller prevents snow or ice incursions that could affect performance upon restarting. With it and the entire system winterized, your irrigation equipment is fully prepped for the long winter ahead.

Winter Protection Tips Based on System Type

The type of sprinkler system you have may require additional considerations for optimal protection against freezing this winter.

In-ground Systems:

• Check for settling around sprinkler risers or heads after soil shifts over the fall or winter, and re-pack with soil if gaps appear.
• Drain anti-siphon valves to prevent trapped water that expands and cracks PVC pipes during deep freezes.

Above-ground Systems:

• Insulate exposed pipes with foam tubes and wrap valve connections to buffer temperature fluctuations.
• Store sprinkler tubing neatly to avoid kinking or damage, perhaps hanging vertically on a wall or shed wall.

Subsurface Drip Systems:

• Blow out emitter laterals thoroughly, being especially vigilant to remove all moisture that could affect dripper performance in spring from expansion freezing.

Zones Used Infrequently:

• Completely drain and disconnect remote zones used seasonally to avoid forgotten moisture pockets causing pipe fractures in rarely used areas.

Spring Startup After Winter

After months of protection from winter’s wrath, it’s time to bring your sprinkler system back to life in the spring. Follow these steps:

Inspect insulation and repairs: Look for any areas where insulation has failed to weather and replace it as needed. Check the system for damage from the winter.

Remove sprinkler head wraps: Carefully peel away any protective coverings used over the winter on exposed sprinkler heads.

Turn on the water at the external bib. Slowly open the shut-off valve that was closed for winter to re-pressurize the pipes.

Purge air from drain valves: Slowly open drain valves one by one to relieve any trapped air pockets and ensure no water accumulates inside from melting.

Blow out lateral lines again if needed. Smaller pockets of trapped moisture may have formed, so gently re-blowing lines helps ensure the best performance.

Check for broken pipes or heads: Carefully inspect for cracks, debris blockages from rodents, or damaged components from freezing or settling.

Run system in inspection mode: open valves zone by zone to check for proper head coverage and emission and make repairs as spots of brown grass re-emerge.

Consider restarting irrigation cycles. Resume watering at reduced intervals as temperatures rise to bring back plants slowly from dormancy.

Winterize for Next Season

Once your sprinkler system has operated trouble-free through the spring and summer months, it’s not too early to start thinking about next fall’s winterization. Taking these preparatory steps well in advance improves protection outcomes:

Check existing insulation for damage or wear and purchase replacements as needed for valves, pipes, and heads. Stock up on other winterizing supplies like blowout plugs and antifreeze caps while vendors have inventory.

Note zones susceptible to freezing based on this year’s performance for focus next season. Consider upgrading vulnerable components, like drain valves, to self-draining for more thorough moisture removal.

Schedule professional winterization services in the early fall before booking up. Trim the landscape close to the ground in late summer or fall to expose sprinkler components.

Review irrigation schedules and cycle times for potential improvements to watering effectiveness.

Record winterization tasks completed this year as a reference for steps to be repeated.

FAQs

Conclusion

Taking some time in the fall to properly winterize your sprinkler system pays off come spring by ensuring everything survives the freezing temperatures intact.

Draining, blowing out, insulating vulnerable areas, and storing components carefully protects your entire system from damage that can otherwise arise from bursting or cracked pipes.

Some simple prevention techniques executed before the first hard frost spares you potentially costly repairs down the road.

And with the right spring startup procedures ensuring no antifreeze remains, your irrigation investment is ready to keep landscapes healthy through another growing season.

By following these winterization tips, you can feel confident leaving your sprinklers in good working order all winter.