Post-Winterization Irrigation Checklist Calgary: 12 Steps to Do Right After Your Blowout

Your sprinkler system just got blown out. The technician left a service record at your door. Now there are 12 things to check and do before winter arrives — and most Calgary homeowners skip all of them.

Why a Post-Blowout Checklist Matters

The blowout removes most of the water from your system. But there are components, settings, and inspections that need to happen after the compressor leaves. Skipping them means you may start spring with broken fittings, a flooded mechanical room, or a controller still trying to run a schedule in February.

The 12-Step Post-Winterization Checklist

Step 1: Confirm the indoor water shutoff is fully closed

The indoor irrigation shutoff (in your mechanical room) must be completely off. Turn the handle perpendicular to the pipe. If it is a gate valve (older homes), turn it fully clockwise until it stops. A partially closed valve can allow a slow trickle into the lines overnight when temperatures drop — enough water to crack a backflow preventer by morning.

Step 2: Set the controller to Off or Seasonal Adjust

Do not leave your controller on Auto. Set it to Off or Rain Delay indefinitely. Some controllers have a Seasonal Off or Winter mode — use it. A controller left on Auto will attempt to run its programmed schedule even in January. Smart controllers (Rachio 3, Hunter Hydrawise) with weather integration will usually stop themselves, but set them to Off manually anyway.

Step 3: Leave above-ground backflow preventer valves at 45 degrees

The technician should have done this, but verify it. The two ball valves on your backflow preventer (the brass assembly outside the house) should be sitting at a 45-degree angle — not fully open, not fully closed. This allows any residual moisture in the valve body to expand without splitting the brass. A backflow preventer left at fully open or fully closed is at higher risk of freeze damage.

Step 4: Check the service record for any repair flags

J.G. Irrigation leaves a written service record at your door after every blowout. Review it for any items flagged for spring attention: a head that did not blow clean, a zone that showed low pressure, a valve that cycled slowly. These are not emergencies in October, but they will be in May if you forgot about them.

Step 5: Photograph the valve box locations

Take a photo of where each valve box is located in your yard before the snow covers them. Mark them on your phone if you have the time. In spring, homeowners regularly call because they cannot find the valve box to tell the technician where to look. A photo in October saves 20 minutes in May.

Step 6: Insulate any above-ground components

If your backflow preventer or any pipe section is above ground and exposed to the elements, wrap it. Use foam pipe insulation from a hardware store. In Calgary, the backflow preventer is the most vulnerable above-ground component — a cracked one costs $350 to $900 to replace in spring. A $5 foam wrap reduces that risk significantly.

Step 7: Book your spring startup now

Startup slots in May fill in April. The best time to book is immediately after your fall blowout while the calendar is still open. J.G. Irrigation customers on seasonal contracts have startup pre-booked automatically. If you are booking individually, call now: 587-433-4795.

Step 8: Test your rain sensor (if your system has one)

After the blowout, disconnect and store any above-ground rain sensor if possible. If your sensor is mounted on the roofline or eave and cannot be removed, check that it is not cracked or waterlogged. A frozen rain sensor in March that stays stuck in “wet” mode will prevent your system from starting in May even when the controller is on.

Step 9: Verify the controller clock and date are still correct

Power outages over winter can reset your controller to factory defaults. A controller that loses its clock will not run schedules correctly in spring. Check in April that the date, time, and zone programs are still intact before your startup appointment. If you have a smart controller connected to WiFi, it syncs automatically.

Step 10: Note any zones that had coverage issues this season

While the lawn is still visible (before snow), walk the yard and note any areas where coverage was uneven, dry, or soggy. Write it down or take a video. In May, you will not remember the specific corner of the front yard where the head was throwing short — but you will spend $120 on a service call trying to find it. A 3-minute walk in October saves time and money in May.

Step 11: Clear debris from valve boxes

Remove leaves, mulch, and debris from on top of and around your valve box covers. Debris holds moisture, which freezes around the box lid and can crack the lid or make it impossible to open in spring. A quick clear-out in October takes two minutes.

Step 12: Plan your backflow preventer annual test

The City of Calgary requires annual testing of your irrigation system’s backflow preventer (cross connection control device). The test must be done in spring by a certified cross connection tester. J.G. Irrigation includes this test at spring startup. If you are not on a contract, book the test when you book your spring startup — the tester needs to submit results to the city, and late submissions can result in a notice.

What Happens If You Skip These Steps

Skipped Step	What Goes Wrong in Spring	Cost to Fix
Shutoff not fully closed	Water trickles into lines, freezes, cracks mainline or preventer	$350–$900+
Controller left on Auto	System attempts to run in December — water hammer, potential line damage	$200–$600
Backflow valves at wrong angle	Trapped moisture freezes in valve body, cracks brass	$350–$900
No insulation on above-ground pipe	Exposed fitting cracks during first hard freeze	$150–$400

FAQ — Calgary Outdoor Lighting Installation 2026

What’s the best time of year to install outdoor landscape lighting in Calgary?

May through September gives the best conditions — ground is soft, crews have full schedules available, and you can see the effect in the long daylight hours. Fall installs (September–October) are possible and popular for homeowners who want their lighting ready before winter. Avoid November–April when ground frost makes cable installation more difficult.

How long does landscape lighting installation take in Calgary?

A typical front yard system (10–16 fixtures): 4–8 hours. Full property (20–40 fixtures): 1–2 days. J.G. Irrigation works efficiently — most installs are complete and operational the day of booking. The system is fully tested and demonstrated before we leave. Call 587-433-4795 for a site visit and installation timeline estimate.