DIY: How to prevent a Sprinkler Blowout

Posted by on Nov 6, 2019 in Winterization | Comments Off on DIY: How to prevent a Sprinkler Blowout

sprinkler blowout
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If you’ve lived in Northern Idaho for a while, then you’ve probably experienced a sprinkler blowout due to the freezing temperatures in Winter. And for the majority of homeowners with lawns, this means work.

Winterizing your irrigation system is very important. If you don’t drain the water from your sprinkler system, then you’ll likely experience a sprinkler blowout.

There are two main ways to drain your sprinkler system. You can do what’s called a quick drain or a blow-out.

You can always have a landscaping company blow-out your system for a fee. However, be one of the firsts to call since landscapers get busier as temperatures begin to fall. If you’re a DIY person though, then read on for the winterization steps to prevent a sprinkler blowout. You’ll need an air compressor for this first option.

Blow out:

  1. Turn off the water shut-off valve to your sprinkler line. It stems off from your main water valve. If not, then you may have to shut off the main water valve.

2. Open the outlet drain and close the backflow outlet. If your system isn’t equipped with an outlet drain valve, we recommended you install one. You can drain your system without an outlet drain valve by blowing air through a petcock, which are the usually two little drain valves located on the side of your backflow device. However, blowing air through these small passages can heat up plastic parts inside the backflow device and warp or crack them.

3. Using your air compressor, connect the hose to the threaded outlet drain valve. This is located near your backflow device. Depending on the compressor hose, you might have to buy an adapter to fit onto the drain.

4. When the air compressor shows 80 lbs. per square inch on the gauge, turn the valve to your first zone. Allow the pressure to push water out of the sprinkler heads for as long as it can. Then, move to the second zone and so forth until you’ve blown out all the zones.

5. If your air compressor is small, you may have to blow out each zone more than once.

6. Once you’re done blowing out the sprinkler system, turn all the ball valves and petcocks to a 45-degree position so they are half open and half closed. This allows any remaining water to drain out.

7. Make sure the line to the sprinkler system in the basement is shut off completely and that you open the inlet drain valve in your basement.

8. Finally, unplug your sprinkler timer, remove batteries, and you’re good for the Winter.

Quick drain

If you don’t have time to blow-out your sprinkler system before the first heavy freeze, here is another alternative:

1. Locate your backflow prevention device and vacuum breaker. This might be found either outside or even in the garage, and it’ll be above ground next to your foundation.

2. Turn off the valve between the backflow prevention device and the main line of your sprinkler system. Then, look for the main shut-off valve to your sprinkler system, turn this off, and open the inlet drain valve (located between the main shut-off valve and the pipe leading outside to your backflow device).

4. Place a bucket under this valve or connect a garden hose to it and direct it to the drain in the floor of your basement.

5. Once the system has been drained, turn all ball valves and petcocks on the outside of your house to a 45-degree angle. This will prevent any water left from freezing and cracking the ball joint.

6. If you decide to recharge the system, just close your petcocks and open up your valves completely. Then, tighten the inlet drain and turn on the sprinkler or main water supply to refill the system.