4 easy steps to winterize your sprinkler system

It’s a bit of a relief when the temperatures start to fall. You can scale back on mowing your lawn, weeding the flower beds and picking bushels of tomatoes. But before you get all cozy inside, you should do a bit of yard maintenance. Once the irrigation water has been turned off, it’s time to winterize your sprinkler system to avoid leaks — and geysers — in the spring.

Turn off automated timers

Turn your timers to the off position to shut your sprinkler system down for the season. If you’re concerned about losing your precise programming, you can set your timer to rain mode instead. This essentially shuts your sprinklers off, but retains all your current settings. Once you turn it back on, you should be back to business.

Turn off water

Turn off the irrigation water at the main water supply. If you’re in the suburbs, it’s likely in the park strip on your property (or near the street). Your local water district cuts the water supply from a central station in the fall. But, it’s still important to turn it off at your home to prevent flooding your box — and yard — when the water is turned back on in the spring. 

Then turn off the master valve, the electric valve which pressurizes the entire system. Once closed, no water will be released into your pipes. Be sure to turn off any backflow valves as well.

Drain lines

After you’ve turned the main line off, there is still water hanging out in your lines. That needs to be drained, because any water left in pipes can potentially freeze. When that frozen water expands, it could bust open your pipes and crack sprinkler heads. If the idea of draining your sprinkler system seems daunting, hire a professional to do the job. If you’re a DIYer, there are few different options.

Manual drain

Depending on your system, you may be able to drain your sprinkler system manually. Your system will have a shut-off valve at the end of each line. Put on a pair of goggles to protect yourself — they’re under pressure. Then, carefully open the valves one at a time and let the water pour out. Once empty, reclose the valve and move to the next one until they’ve all been drained.

Automatic drain

If your system has an automatic draining function, your job is a bit easier. Once the main valve is closed, run the sprinklers for a few minutes to empty the pipes.Then, remove any lingering water from the individual valves by loosening the solenoid — the plastic cap with wires. Once air enters your system, the remaining water should flow out.

Blow out

If you don’t have drain valves, you can hire a professional sprinkler service. They’ll likely use an air compressor to blow the water out. If you’re doing it on your own, use a compressor capable of 20 to 50 cubic feet per minute, with 50 pounds per square inch for flexible black pipe or 80 psi for rigid PVC pipe. Don’t attempt to use this method if your sprinkler system wasn’t designed for it, as you could damage your pipes, heads and valves — exactly what you were trying to avoid in the first place.

Insulate above ground parts

Sprinkler system parts that are above ground are also susceptible to winter damage. Protect your main shut off valve, exposed pipes and backflow valves with insulation tape and foam covers. Be sure not to block the drain outlets and air vents on the backflow preventers.

Now you can sit back and relax — once all those leaves are raked, of course. Find more winterization tips on the KSL Resource Center.