Express Sprinkler Blowout: What to Do Before and After Your Service

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Our Express Sprinkler Blowout service is designed to be a flexible and economical way to winterize your sprinkler system. Because this service focuses on clearing exterior sprinkler lines only, there are a few important steps homeowners must complete before and after our visit to ensure the system is fully protected.

Please review the instructions below carefully.

⚠️ Important: This Page Is for Express Blowout Customers Only

If you are not scheduled for an Express Blowout and are trying to protect your system ahead of a freeze, do not follow these steps.
Use our Freeze Protection Guide instead.

These instructions apply only to customers receiving our Express Blowout service.

What to Do Before Your Express Blowout Service

1. Shut Off Water to the Sprinkler System

Before we arrive, turn off the water supply feeding your sprinkler system.

This valve is typically located:

  • In a basement
  • Crawl space
  • Utility room
  • Near where the irrigation line exits the home

After shutting off the valve, briefly run a sprinkler zone to confirm there is no active water pressure.

2. Do NOT Drain or Open the System

This is critical.

Do not:

  • Open the backflow device
  • Open test cock valves
  • Open valve box drains
  • Manually open or leave open in ground valves

For Express Blowout service, the system must remain closed so we can properly clear each zone using compressed air.

Opening drains or valves before our arrival can prevent us from building the pressure needed to fully blow out the system.

3. Ensure Access to Exterior Valve Boxes

If your system has exterior in-ground valve boxes:

  • Make sure they are visible and accessible
  • Remove dirt, debris, rocks, or mulch covering them
  • If they are behind or covered by a plant/shrub clear out a path for easy access

This allows us to efficiently clear each zone during service.

NOTE: You Do Not Need to Be Home

For most Express Blowout services, the customer does not need to be home as long as:

  • The water is shut off
  • Exterior valve boxes are accessible

What We Do During Express Blowout Service

During our visit, we:

  • Use exterior in-ground valves to activate each zone
  • Clear water from exterior sprinkler lines using compressed air
  • Do not drain interior plumbing or piping inside the home

Because this is an express service, interior draining is the homeowner’s responsibility after we leave.

What to Do After Your Express Blowout Service (REQUIRED)

Your sprinkler system is not fully winterized until the following steps are completed.

1. Drain Interior Sprinkler Lines

Return to the valve you used to shut off water to the sprinkler system.

Most shutoff valves include a small drain port, often covered by a brass cap. Some systems may also have a drain spigot located next to the valve or inline on the pipe leading to the backflow device.

Open the drain and allow any remaining water to empty into a bucket or container.

If water sprays out under pressure, the water has not been fully shut off or the incorrect valve was used.
Close the drain and confirm the correct sprinkler shutoff valve is completely off before proceeding.

2. Open the Backflow Device to Drain Remaining Water

After service, set all isolation valves on the backflow device to a 45-degree angle, including:

  • Inlet valve
  • Outlet valve
  • Test cock valves

This allows air into the system and lets any remaining water drain out of the backflow assembly.

3. Leave the System Open for the Winter

Once drained:

  • Leave backflow valves at a 45-degree angle
  • Leave the system unpressurized
  • Do not turn the water back on until spring

What NOT to Do

  • Do not forget to drain interior lines after service
  • Do not leave any manual drain valves open if they were briefly used
  • Do not repressurize the system after blowout
  • Do not assume the system is protected without completing these steps

Most winter damage occurs when interior lines are left full of water.

Final Reminder

The Express Blowout service clears exterior sprinkler lines only.
Interior draining is required and must be completed by the homeowner.

Completing the steps above ensures your sprinkler system is properly protected for winter.

If you require a guaranteed service date, prefer that we handle all system draining, or are unfamiliar with your sprinkler system and would like guidance before trying our Express Blowout service in the future, ask us about our Full Sprinkler Winterization option.