How to Turn Off Your Sprinkler System in Calgary: Shutoff Valve, Controller, and What Comes Next

Turning off your Calgary irrigation system is something you can do yourself — but there are four distinct steps, and skipping any one of them leaves your system at risk of freeze damage. This guide covers all four in the correct order.

What “Turning Off” a Calgary Sprinkler System Actually Means

Many Calgary homeowners believe turning the controller off or to “RAIN DELAY” mode constitutes turning off the system. It does not. The system remains fully pressurized with water in all lateral lines when only the controller is off. Complete system shutdown requires four separate actions working together.

The Four Steps to Correctly Turn Off a Calgary Irrigation System

Step 1: Set the Controller to OFF Mode

Turn the irrigation controller to OFF mode — not RAIN DELAY. RAIN DELAY mode puts the system in standby for a temporary weather pause and will resume automatic watering after the delay period. OFF mode prevents all automatic watering cycles. Most Calgary irrigation controllers have a dedicated OFF position on the mode dial. Smart controllers (Rachio, Hunter Hydrawise) have a system pause or disable function in the app. If you cannot determine how to set your controller to OFF, call J.G. Irrigation at 587-433-4795 for a controller support visit.

Step 2: Close the Main Irrigation Shutoff Valve

The main irrigation shutoff valve controls water supply to the entire irrigation system. Closing this valve is the most important single action to protect your Calgary sprinkler system from freeze damage. Location: typically in the mechanical room or basement, on the pipe that supplies the irrigation system (separate from the main household water supply). Turn the shutoff valve handle clockwise to the fully closed position. If the handle is a ball valve, the handle should be perpendicular (90 degrees) to the pipe to indicate closed. If the handle is a gate valve (round, multi-turn), turn it fully clockwise until it stops.

Important: Closing the irrigation shutoff does not drain the water already in the lateral lines. For that, a professional blowout is required.

Step 3: Drain the Backflow Preventer

With the irrigation shutoff valve closed, locate the backflow preventer assembly (the brass assembly on the exterior wall or in a utility box). The assembly has two small test cocks (valves with a flat-blade screw slot on top) and a center relief valve. Turn each test cock 90 degrees to the closed position (slot across the pipe, perpendicular) to prevent water from draining through the test cock ports during winter. Do not remove the test cocks or leave them open — the test cocks in the winter position are 90 degrees from the operating position.

If you are not sure about the backflow preventer, do not attempt this step yourself — ask your J.G. Irrigation technician during the blowout visit to demonstrate the winter positioning.

Step 4: Schedule (or Confirm) Your Professional Blowout

Steps 1 through 3 are preparation steps — they reduce risk but do not complete winterization. The only step that actually removes water from the lateral lines is the professional compressed air blowout using a commercial 185 CFM compressor.

If you have already closed the shutoff and turned off the controller, your system is partially protected but not fully winterized. Water remains in every lateral line. A professional blowout is still required before the first hard frost in your Calgary community.

Call J.G. Irrigation at 587-433-4795 for blowout scheduling. Community deadlines: Airdrie October 1, Cochrane October 2, Calgary NW/SW October 5, Calgary NE October 7, Calgary SE October 8.

What to Do If You Cannot Find Your Irrigation Shutoff Valve

The irrigation shutoff valve is separate from the main house water shutoff. Common locations in Calgary homes:

• In the mechanical room, on a pipe branch labeled “irrigation” or with a red handle
• In the basement ceiling directly below the backflow preventer location
• Near the water meter, as a valve on a branch line separate from the main household supply
• In a buried outdoor valve box near the backflow preventer

If you cannot locate the irrigation shutoff valve, call J.G. Irrigation at 587-433-4795. We identify and label the irrigation shutoff valve on all service visits — it is part of every spring startup and fall blowout walkthrough.

Common Mistakes Calgary Homeowners Make When Turning Off Their Sprinkler System

• Setting the controller to RAIN DELAY instead of OFF — the system resumes automatic watering after the delay period, potentially running after a hard frost
• Closing the shutoff but skipping the professional blowout — water remains in all lateral lines and is still at risk of freezing in the first hard freeze event
• Disconnecting the controller power without setting it to OFF first — many controllers return to their last programmed schedule when power is restored
• Assuming the system is off because no zones ran during the first frost — the frost may not have triggered the controller rain skip, and water in the lines is still at risk

J.G. Irrigation performs all four steps correctly on every fall blowout visit. Written service receipt confirms controller OFF mode, shutoff valve closed, backflow preventer drained, and zone count blown. Call 587-433-4795.