How to Blow Out a Sprinkler System? – [Winterize Sprinkler System]

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Those who live in colder regions of the world know how important it is to have all your outdoor equipment prepped for winter and spring. One of such garden equipment that needs your utmost attention is your sprinkler system.

You risk serious damage to your sprinkler system if you fail to clean or blow them out adequately. Once temperatures begins to rise, it gets increasingly difficult for yard equipment to perform optimally. Garden sprinklers such as impact sprinklers or oscillating sprinklers can stop functioning properly. Even your sprinkler controllers can face issues due to freezing cold.

To save yourself from the costly freezing damage you need to blow out the water from your sprinkler system. If you have the money, landscaping companies can help blow out your sprinkler system for a fee but if you don’t have the extra funds and want to do it yourself, follow the outlined steps below.

Blowing out your Sprinkler System

Step 1: Shut the Main Valve off

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Step 2: Properly Drain Out the Water Through Outlet Valve

Now that the main valve has been shut off and there is no water supply to the sprinkler system, make sure the outlet valve or drain pipe is open. This will ensure that any leftover water is properly drained out. You would normally catch the water flowing out of the system with a large bucket. Get ready for a spurt of water because of the pressure within the pipes or a rubber hose if you’re using that.

Step 3: Connect the Main Valve to the Hose of Air Compressor

At this stage you will need an air compressor. Make a connection from the threaded main valve head to the hose from your air compressor. If they don’t fit, go online and buy a suitable adapter that fits into the drain pipes.

Step 4: Install an Outlet Drain Pipe to the Petcocks

If your system doesn’t have an outlet drain pipe you will have to install one. Although you can blow out your sprinkler system without an outlet drain pipe, it isn’t recommended because blowing air through the petcocks can heat your system and severely damage small plastic parts within the system. You can also use a garden hose for this job.

Step 5: Push Out the Water With the Help of Air Compressor

Using the air compressor blow out your system by turning the valve on (towards the left) and allowing the pressure to push out the water from the system. Replicate this from zone to zone until you have covered the entire yard of your garden.

Step 6: Turn the Valve Open to About 40-45 Degrees

Once you have completely blown out your system with the required compressor pressure; turn the valves open to about 40 to 45 degrees. This will mean that they are half open and half closed.

Step 7: Repeat the Process

Repeat the blowing out process all over again with the valves half open and half closed. This process has the desired effect of completely draining out any water left behind.

Step 8: Keep the Sprinkler System’s Main Valve Completely Shut off

Please ensure that your sprinkler system’s main valve is completely shut off to avoid any water from seeping in to refill the system. Use a 2 minute time interval to blow out each sprinkler zone. Finally, unplug the compressor batteries and detract the compressor hose from the main sprinkler thread head.

Quick Drain Procedure for Blowing Out Sprinkler System

The blow out procedure illustrated above can be time-consuming to the extent that not everyone will have the proper time to do it. What is important is that you must flush out your system before the first big freeze happens.

You can alternatively quickly drain out your system by following the laid down procedure below.

Step 1

Go to the garage or outside the house to locate your backflow device or vacuum breaker. Ideally, it is located above ground level.

Step 2

There should be a valve that connects the backflow prevention device to the sprinkler system going underground. Locate that valve and make sure you shut it.

Step 3

Go straight to the basement and locate the main sprinkler valve to the system. Now shut off this valve and open the inlet drain valve. You will find the inlet drain valve between the backflow device and the main shut off valve.

Step 4

Place a large bucket at the inlet drain valve to collect water draining out from the sprinkler system. Better still; connect a hose pipe to the inlet valve to channel the water towards the irrigation system at the basement floor.

Step 5

The drains should begin immediately. Give it about 10 to 20 minutes to completely drain out. Once the water has been drained out, it’s time to turn all valves and petcocks to 40-45 degrees. Leaving the valves and petcock half open and half close will ensure water left completely drains out of the system.

Step 6

If you still need to recharge or refill your sprinkler system, close the petcocks and open the valves completely. Turn the main sprinkler system open and fill the pipes with water while shutting off the inlet drain pipes.

Safety Procedure for Winterizing Sprinkler System

While blowing out your sprinkler system, please ensure you adhere to the following safety rules to avoid accidents:

  • If your system already has frozen water in it, avoid using a blowout flame or torch to thaw the pipes.
  • Stick to a blowout pressure of 60 psi from the compressor. Do not overload the pipes with high compressor pressure in an effort to drain the pipes rather half open the valves to remove all water from the pipes.
  • After a prolonged period of cold temperatures carry out a drain test of the sprinkler system to see if the mains are frozen. Fill the system with water and let it run out. Fill the system again with water and allow it to run out for the second If the pressure stays the same the pipes are clear, if not you will need to clear out the ice clogs.

On that Note

Sprinkler system requires that they are maintained annually so that trapped water underneath is removed. If they can clog the pipes and the freezing water within can burst the pipe open.

Year in year out there has been accidents involving sprinkler systems within and around the house due to bad maintenance. To avoid leaking pipes underground carry out the blow and drain out maintenance procedures listed above.

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