How to Wake Up Your Sprinkler System Without Wrecking It
TL;DR Spring startup isn’t just turning a valve. Do it wrong and you’ll blow a head, crack a line, or flood a zone before the season even starts. This guide walks you through the right sequence so you can get your system running cleanly, catch any winter damage early, and head into summer without surprises.
Key Takeaways
- Never open the main valve fast — pressurizing slowly is the single most important step
- Walk every zone manually before you trust the controller to do it automatically
- Check the backflow preventer first — it’s the piece most people forget and the one that matters most
- Broken heads and uneven coverage are totally normal after winter and easy to fix yourself
- If you find a cracked line or a zone that won’t pressurize, call a plumber before running the system
The Process at a Glance
- Inspect the backflow preventer before touching anything
- Check and update the controller schedule
- Pressurize the system slowly, a quarter turn at a time
- Walk each zone manually on two-minute test runs
- Fix what you find, then lock in your full schedule
Why Spring Startup Is Worth Doing Carefully
Here’s what most people do: turn the water on, punch in a schedule, and walk away. And honestly, most years that works out fine — right up until the year it doesn’t, and suddenly there’s a geyser in the garden bed.
Your system has been sitting completely idle through a Surrey winter. Freeze cycles, pressure swings, months of zero use. Fittings contract and expand. Small cracks form. Heads shift. None of it is visible from the outside until the water’s running, and it’s too late.
Spend two hours on a weekend morning doing this properly, and you’ll catch those problems early, when they’re still a quick fix. Skip it, and you might spend July staring at a dead patch, wondering what went wrong.
What to Do Before You Touch the Water
Check the Backflow Preventer First
This is the part most people walk straight past — don’t be most people.
The backflow preventer sits on the outside of your home where the irrigation line branches off the main water supply. Its whole job is to stop irrigation water from getting pushed back into your drinking water, which makes it genuinely important and not just a formality.
Give it a proper look before you touch anything else. You’re checking for:
- Cracks in the housing or fittings
- Mineral buildup or corrosion around the valves
- Test cocks that are seized or simply won’t turn
If it looks damaged or the test cocks won’t budge, stop right there and call a plumber. Running the system through a compromised backflow preventer is a plumbing code issue, and it makes the situation worse rather than better.
Confirm the Controller Is Ready
Last summer’s watering schedule is still loaded. Spring needs something very different.
Pull up the controller, check it has power, and take a good look at what’s programmed. A lot of homeowners forget the August schedule is still sitting there from when they last touched the thing.
Spring needs shorter run times and less frequency than summer. Hit run without checking first and you’ll oversaturate everything in the opening week and wonder why the lawn looks worse than when you started.
Pro Tip
Before running any zone on its schedule, set each one to manual mode for exactly two minutes. That’s plenty of time to check coverage and spot problems without soaking the yard. Lock in your full seasonal schedule only after you’ve confirmed every zone is behaving the way it should.
How to Pressurize the System
This is where most DIY startup mistakes happen, and the fix is genuinely simple: slow down.
A system that’s been dry all winter has air sitting in every line and every zone. Open the main valve too fast, and that air has nowhere to go quickly enough. The pressure surge can blow fittings, crack heads, and knock out solenoid valves before you’ve even run a single test.
Here’s the sequence that sidesteps all of that:
| Step | What to do |
|---|---|
| 1. Find the shutoff | Locate the irrigation main shutoff, which is separate from your home’s main water supply |
| 2. Open slowly | Turn it a quarter turn, then pause for a full thirty seconds |
| 3. Keep going gradually | Continue opening over two to three minutes until it’s fully open |
| 4. Listen and wait | Continue opening for over two to three minutes until it’s fully open |
| 5. Check for leaks | Look around the backflow preventer for any drips or weeping before moving on |
Slow and steady here genuinely saves you a lot of head-scratching later. It’s one of those things that feels unnecessary until the one time you skip it.
How to Walk Your Zones
Once the system is pressurized and quiet, run each zone manually, one at a time, for two minutes each.
Walk the zone while it runs and keep your eyes open for these four things:
- 🔧 Broken or tilted heads: uneven spray pattern or water shooting off to the side
- ⬇️ Sunken heads: settled below grade and struggling to pop up fully
- 🌿 Dry patches: usually a clogged or missing head that’s not reaching the area
- 💧 Soggy ground before the zone even activates: a sign of a leaking valve or a crack underground
Most broken heads are a ten-minute fix. Pull the head, match the model at your local hardware store, and swap it in. No special tools, no drama, no plumber required.
Pro Tip
Take a photo of each zone while it’s running, same spot and same angle every spring. You absolutely will not remember which head in zone four had the weak pattern six months from now, but a running photo record turns future troubleshooting from an hour of guesswork into a five-minute job.
When to Call a Plumber Instead
Most of what you find at startup is completely DIY-friendly. But some things genuinely need a licensed plumber, and knowing the difference saves you time, money, and a flooded lawn.
| Handle it yourself | Time to call a plumber |
|---|---|
| Broken or sunken sprinkler heads | A zone that won’t pressurize at all |
| Controller programming and scheduling | Soggy ground over a line that isn’t running |
| Tilted or misaligned heads | A damaged or non-functional backflow preventer |
| Valve adjustments | Water getting back into the house supply when zones activate |
Underground line repairs and backflow preventer replacement need a licensed plumber every time. Everything else, heads, controller settings, valve adjustments, you’ve genuinely got this.
The Bottom Line
Two hours on a spring weekend morning is all it takes to start your system properly, catch any winter damage while it’s easy to fix, and head into the season feeling good about it.
Pressurize slowly, walk every zone, sort out what you find while it’s still accessible. If something’s off after startup — a zone that won’t fire, pressure that won’t hold, a backflow preventer that’s seen better days — don’t just run the system and cross your fingers.
Give Mark a call at 604-897-4989. Get a free assessment. Know exactly what you’re dealing with before summer arrives.
Written by Mark, South Surrey Plumber. Licensed and locally owned — serving Surrey, White Rock, and the surrounding area for over 20 years.
