How to Winterize Sprinkler System Like a Pro: Step-by-step Instructions

When to Winterize

The ideal season to protect the sprinkler system from freezing is highly dependent on the weather in the area. Overall, the system is supposed to be ready prior to the initial hard freeze of the fall. A rough guide would be to winterize when temperatures drop to stay at or below 60–65 °F on a daily basis because cold nights may turn water in the lines into ice very quickly.

Due to the changing weather throughout the year, homeowners cannot just look at the calendar. Rather, they should check the local weathercast and listen to the average dates of frost in their area. It is better to act slightly before it is too late because even a single local cold snap may cause some pipes to freeze and cause considerable damage.

In individuals opting to seek professional assistance, it is also appropriate to book the service early in the season. In late fall, sprinkler companies can become busy as people are all trying to prepare their systems at once. One can save money and prevent delays by booking an appointment.

1. Inspect the System

Before closing up for the winter, it's essential to check the sprinkler system over. This stage aids in locating potential problems that could plague you in the winter, and the system is in its best condition before draining.

• Check Sprinkler Heads: As homeowners, you are supposed to take a tour of the yard and examine every sprinkler head. Cracked or clogged, or uneven spraying heads need to be repaired or replaced. Make any of the heads that have moved out of position, upright, and distribute water accordingly.
• Look for Leaks or Weak Spots: Leaks can be hard to detect, but can cause damage overall unless noted. Evidence such as puddles, wet areas, or lots in the lawn that are greener than the rest are such telltale signs. These can be indications of damaged fittings or breaks in the pipelines in the ground. By managing them at this stage, it is possible to eliminate further damage that may be caused during the cold months.
• Inspect and Clean Filters: Filters and screens trap dirt and debris during the watering season. When they get clogged, there is limited water flow and such that it might not drain well. By cleaning or replacing filters prior to winter, the system will run well when it is restarted in the spring.
• Make Repairs Before Winterizing: Once an inspection has been done, any issues that are found need to be addressed immediately. Even minor problems might result in expensive repairs in case of freezing water, creating additional pressure on the system. Making repairs now will result in complete draining of the system and its protection during the winter.

2. Shut Off Water Supply

After inspection the water supply should be switched off after the system has been inspected. This eliminates the entry of more water into the pipes and safeguards the system against pressure development when there is freezing weather.

• Locate the Main Supply Valve: The main supply valve normally can be located at a point where the sprinkler system attaches to the home plumbing. It can be in the basement, crawl space, utility room, or outside on a ground valve box. When found, the valve must be completely turned off to shut down the valve of water being passed through the sprinkler lines.
• Turn Off “Stop and Waste” Valves (If Present): On some systems, there is a so-called stop and waste valve installed between the main and the backflow preventer. This special valve not only stops water, but also allows all remaining water to drain out of the line. In case there is one, the system should be turned off and opened so that water can come out.
• Shut Valves in Crawlspaces or Basements: In certain buildings, particularly older buildings, additional shut-off valves sometimes can be found in less-obvious locations: inside a crawl-space, inside a basement, or in a mechanical room. These locations should be inspected, and valves to the sprinkler system should be completely closed.

3. Disable the Controller

The sprinkler controller should be disabled once the water is shut off. This avoids winter cycles running by the system and saves the components from preventable wear.

• Switch to Rain Mode:  Most newer type sprinkler controllers will have a setting called “rain mode” or “off.” The ability to switch to this mode prevents the system from watering, preserving the programmed schedule.
• Fully Power Off if Needed: There should be no rain mode on the controller. The controller can be turned off in its entirety. This is a conservative means of shutting it down, but there is one limitation, all the programmed settings will be lost unless there is a battery backup for the controller.
• Indoor and Outdoor Controllers: Rain mode is typically the simplest with outdoor controllers. The controllers are indoors, one can also have them powered off to save on electricity, but it is equally as useful to have them remain on rain mode.

4. Drain the System

The most important step in winterization is draining the system. Minor traces of water within the pipes could freeze, expand, and crack or break. The different method adopted depends on the sprinkler system in use.

a) Manual Drain

Valves on systems that should be drained manually are located at points of lowest unusable pressure, and also at the ends of the piping system. The water is made to escape through these valves by natural gravity.

• Locate Drain Valves: Find manual drain valves. They are normally fitted low, more towards the end of the lines, and occasionally close to the backflow preventer.
• Open Valves Slowly: Open the valves gradually to drain the water out. One line should be worked upon at a time, a main line first, and the smaller branches second.
• Check Sprinkler Heads: Water might be trapped inside the system in case there are check valves placed on the heads. Manually pull up the sprinkler heads to allow this water out.
• Close Valves: When the water has been completely drained, cover all the valves to avoid water contamination by dirt or insects entering the pipes.

b) Automatic Drain

Automatic drain valves are provided on some sprinkler systems to drain the water each time the water pressure is not inside the pipes is too low. This makes draining easier, though this also needs a little attention.

• Shut Off the Water Supply: As in the earlier steps, the supply should then be intercepted at the main.
• Relieve Pressure: Flush one sprinkler nozzle until the pressure decreases within the pipes. Automatic valves will then open up, and water will automatically flow out through them at that time.
• Check for Residual Water: If it is an automatic system, it cannot get you all the water out. Small spills may be left in the valves, fittings, or backflow device. It is quite sensible to open progressively a test cock or valve briefly, to make sure of the absence of any water collected.

c) Blow-Out Method (Compressed Air)

The most comprehensive means of clearing water in the sprinkler pipes is the blow-out method. It blows water out the lines and sprinkler heads with compressed air. Connect the air compressor in the system at a quick coupler, a hose bib, or a fitting placed directly following the backflow preventer. At no point you should ever connect the compressor directly to the backflow. This can be damaging:

• Ensure that the supply of water is fully stopped.
• To protect the backflow preventer valves, close them.
• Begin with the most remote and upper tier of the territory, furthest removed in point of distance to the water supply. Switch it on with the controller.
• Gradually feed on the compressed air, with PVC pipes limited to no more than 80 psi and polyethylene pipes being limited to no more than 50 psi.
• Press the water out of the heads with the air until it is dry air only.
• Move through every zone at a time till the system is clear.
• Uncouple the compressor, and open some trap valve or test cock to relieve the pressure.

Safety Precautions

• Wear eye protection and never do a blow-out without them.
• Do not stand over spouts of sprinklers, people, when air is in motion.
• Before commencement, remove any flow sensors or any sensitive parts.
• Do not leave the compressor alone.
  
  

5. Insulate Above-Ground Components

The system is not entirely underground after being drained, so even freezing temperatures could still affect it. These vulnerable parts can be well insulated, and this prevents expensive repairs.

• Main Shutoff Valves: Many of the main shutoff valves can be insulated with foam tape, insulating tubes, or by placing a weatherproof cover over the main shutoff valve. Since this is the valve that governs the whole system, safeguarding it will give the system a possibility of being restarted in the spring with no leaks.
• Backflow Preventers: Backflow preventers are especially vulnerable because they sit above ground and contain delicate parts. They should be covered with an insulated bag or wrapped with foam insulation. However, care must be taken not to block the air vents or drain outlets, since these need to stay open to function properly.
• Exposed Pipes: All exposed pipes commonly seen need to be covered using foam-insulated sleeves or straw or mulch in case they are approaching the ground. This additional step will protect against dramatic temperature changes.
• Outdoor Faucets and Hose Bibs: The faucets leading to the sprinkler system are supposed to be covered with insulated faucet covers. It is important that hoses be removed, emptied, and stored inside buildings to avoid frozen water in them.

General Garden-Care Tips

To prepare the sprinkler system during the winter season, the homeowner should detach any watering items, coil hoses can be rolled so that they can be stored easily, and also should leave the insulation until next spring. These minor actions safeguard the sprinkler system as well as the plumbing of the home against frozen water.

6. Final Checks & System Shutdown

Once the system has been drained and insulated, there are a couple of finishing touches to help the system endure the winter. The checks also minimize the chances of damage and facilitate spring start-up.

• Close Valves Correctly: When finished draining, all valves must be closed, except those noted. In one example, test cocks of the back flow preventer are usually left open so that any entrapped moisture can dissipate. This allows any remaining water to drain and prevents it from freezing inside the unit.
• Confirm Controller Settings: None of the watering cycles should begin in the winter. In the case of indoor controllers, it is possible that keeping the power on in the rain mode will serve to avoid condensation in the unit. The outdoor controllers are expected to remain in rain mode and covers closed so they are not exposed to snow and rain.
• Secure and Label Components: It would also be useful to label the shutoff valves, the drains, and some critical parts of the system before winter. This is time-saving during spring when the system is re-fired. Saving any small component, such as filters or caps, in a safe place also prevents loss.

Safety and Maintenance Tips

Pets and children must be kept out of the work area during blow-outs. It is also a good idea to wear hearing protection, as air compressors can be extremely loud. Lastly, after the first spring, the system must again be checked to ensure that there has not been damage over the winter.

The Bottom Line

A winter prep sprinkler system is the process every homeowner should take when living in places where winters are very cold. It is simple and every action provides protection and ensures that the system will be winter-ready. Winterizing can appear to be an unnecessary hassle, but it saves money and headaches in the long-term perspective. The owners of the houses can perform it on their own by employing some basic steps. Otherwise, they can call professionals.

Growcycle offers guides on sprinkler winterization. It also provides useful guides and material to maintain gardens, lawns, and outside systems in good condition, the whole year round.

Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or any other form of professional advice.