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In Canada, the fall visit is the one that can't be skipped. Water trapped in pipes, heads, valves and the backflow preventer freezes and splits them, and the damage only shows in spring when the water goes back on. The connection to the drinking water supply and municipal watering rules add a regulatory layer that a good contractor handles as part of the job.
This page focuses on the service side of owning a sprinkler system: what each type of visit includes, installing heads around sod, driveways and snow clearing, the ways to winterize, backflow preventers and watering rules, controller and sensor upgrades, repairing or replacing an older system, and what to do when something breaks. Zones, head types and drip lines are explained in the irrigation guide.
Sprinkler system services: installation, repair, spring start-up, fall blow-out and service plans
- New installation: design, trenching, heads, valves, controller and the connection to the water supply, usually for the lawn plus nearby beds.
- Repairs: replacing broken heads and nozzles, fixing cracked pipe and fittings, and tracing faulty valve wiring.
- Spring start-up: turning the water back on, testing every zone and adjusting heads before the watering season.
- Fall winterization: shutting off and draining the system, clearing the lines and protecting the backflow preventer from frost.
- Mid-season check: a coverage test and schedule change when summer heat or local watering rules shift.
- Upgrades: new controllers, rain or soil moisture sensors, and converting beds from spray heads to drip.
- Service plans: start-up, one or more checks and winterization bundled into one seasonal agreement.
Installing an in-ground lawn sprinkler system: timing, head placement and utility locates
The easiest time to add sprinklers is before new sod, seeding or paving, when trenches and sleeves under future walkways cost the lawn nothing. Placement decisions made at installation decide how well the system survives mowing, snow clearing and Canadian winters for years afterward.
- Public utility lines must be marked before any trenching; in Ontario, locate requests go through Ontario One Call.
- Private lines, such as a garage feed, a barbecue gas line or buried lighting cable, aren't covered by public locates and need tracing separately.
- Heads set flush with the finished grade survive mowers far better than heads left sitting high.
- Heads and pipe kept back from driveway and sidewalk edges escape plows and snowblowers, and snow-pile areas are marked on the plan.
- Spray patterns are aimed away from the foundation, windows and the street.
- A blow-out connection or drain points are included so winterizing is quick and complete.
Sprinkler winterization methods and what to watch after spring start-up
There are three common ways to winterize. A compressed-air blow-out, the usual choice for in-ground lawn systems, pushes water out one zone at a time. Manual drain valves at the low points let water run out by gravity, which only works when the pipe was laid sloping toward them. Automatic drain valves open when pressure drops, but they can leave water in low spots and fail without anyone noticing. Whatever the method, the irrigation shutoff inside the house is closed and the pipe between it and the backflow preventer is drained.
Blow-outs are best left to a technician. Too much air pressure can crack fittings and blow heads apart, air run too long through an empty zone can overheat plastic pipe, and a pressurized line that comes apart can injure someone. After the spring start-up, keep an eye on the system for the first few weeks.
- A water meter that keeps moving while the house and sprinklers are both off points to a hidden leak.
- Soggy spots or small sinkholes along a pipe route suggest a cracked line or fitting.
- A zone that waters after an overnight rain means the rain sensor needs adjusting or replacing.
- Heads that spray the driveway, house or street after dethatching or topdressing need resetting.
- Weak or lopsided spray usually comes from nozzles clogged by grit over the winter.
Backflow preventers and watering restrictions for lawn sprinkler systems
The backflow preventer keeps lawn water, which can carry fertilizer, pet waste and soil bacteria, from being siphoned back into the house supply and the city's mains. On lawn systems it is usually an above-ground assembly where the sprinkler line branches off, such as a pressure vacuum breaker, a double check valve assembly or a reduced pressure assembly; plumbing codes and municipal by-laws decide which type is required and whether it must be tested. Toronto runs a backflow prevention program with testing by certified cross-connection control specialists, and other cities have programs of their own. Because the device usually sits outdoors, it is often the first part to freeze, so winterization drains it or removes it for the season.
Watering rules then govern how the system runs. Montreal limits automatic systems to 3 to 6 a.m. on even or odd days matching the address, and many other municipalities set their own hours and can ban lawn watering during a drought or heat wave. Reprogram the controller to your city's current rules at every spring start-up.
Adding a smart controller or rain sensor to an existing sprinkler system
Most older systems can be upgraded without digging. A rain sensor mounts outdoors and wires to the controller, and a weather-based controller usually replaces the old timer on the same zone wires. Either upgrade pays off only with proper setup, with each zone programmed for its heads, sun and soil, so have the technician do it during a start-up or service visit.
- Make sure the new controller has enough zone stations for the system, plus a spare for future beds.
- Mount the rain sensor where it catches open rain, clear of eaves, trees and sprinkler spray.
- Label every zone wire before the old timer comes off so each zone stays matched.
- Confirm the controller can follow your municipality's allowed days and hours, including odd-even schedules.
- Check that a controller relying on a wireless connection gets a reliable signal where it is mounted.
Sprinkler repair or replacement: when an older system is worth fixing
Most sprinkler repairs are small: a head cracked by a mower, a nozzle clogged with grit, a fitting split by frost or a valve fouled by debris. Those are routine even on an old system. Replacing some or all of it starts to make sense when breaks keep returning to the same brittle pipe, when coverage was poor from the start, or when the yard has been redesigned and the old zones no longer fit.
- Repair: isolated broken heads, a single leaking fitting, or one zone with a failed valve.
- Retrofit: replacing mismatched heads within a zone so they all apply water at the same rate, and adding a new controller.
- Partial redesign: splitting an overloaded zone, rerouting around a new patio or converting beds to drip.
- Replacement: repeated breaks in aging pipe, pressure that can't reach the far heads, or an unmapped system nobody can service efficiently.
- Before agreeing to replace a whole system, ask for a written zone-by-zone assessment.
Sprinkler emergencies: a zone that won't shut off, a burst line or a split backflow preventer
If water won't stop, switch the controller off first. If the zone keeps running, close the irrigation shutoff, usually a valve on the supply pipe inside the basement or utility room where the sprinkler line leaves the house. A burst pipe, or a backflow preventer split by an early frost, calls for the same step, then a technician visit, since water pooling against the foundation can find its way into the basement. Learn where that valve is, and label it, before you ever need it.
Sprinkler Systems: frequently asked questions
Can I blow out my sprinkler system myself?
It's possible, but the risks are real: too much pressure cracks fittings, air run too long through dry pipe can overheat it, and parts under pressure can come apart. A technician uses equipment sized for the job and leaves the backflow preventer ready for winter, which is why most homeowners book it.
When should I turn my sprinkler system on in spring?
Once the ground has thawed below the pipes and hard frosts are over. Opening the supply too early can crack pipe that is still frozen. Book the start-up before the spring rush, and set the controller to this year's municipal watering rules.
Why does my sprinkler system run when it's raining?
Either there is no rain sensor, the sensor has been bypassed, or it needs cleaning or replacing. A technician can add or fix one, or install a weather-based controller that skips cycles after rainfall.
How do I keep snow plows from breaking sprinkler heads?
Keep heads back from driveway and sidewalk edges at installation, stake their locations before the first snowfall and show your snow removal crew where they are. Heads damaged over the winter are replaced during the spring start-up.
Where is the shutoff for my sprinkler system?
Usually on the supply pipe inside the house, close to where the sprinkler line exits, and sometimes also in a valve box outside. Ask your installer or service technician to show you and label it so you can stop a burst line quickly.
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Written by the LokalMatch editorial team. Reviewed by Zubair Afzal on September 10, 2026. How we write and check our guides