It’s spring. You go to turn your sprinkler system on for the first time and… nothing happens. No water, no pressure, or the controller shows an error. Don’t panic — most of the time this is a simple fix. Here’s a step-by-step guide to diagnosing why your sprinkler system won’t turn on after winter, and when it’s time to call a pro.
Step 1: Check the Controller First
Before assuming something is broken, check your irrigation controller:
- Is it getting power? Check that it’s plugged in and the outlet is working. Many controllers have a battery backup — if the battery died, it may have lost its programming.
- Is it in “rain” or “off” mode? Some controllers have a rain delay button or bypass switch that can be accidentally activated. Look for a rain sensor override or seasonal adjust setting.
- Is the date and time correct? If the controller lost power or battery, the schedule may need to be reprogrammed.
- Are the zones set to run? Check that each zone has a watering duration assigned and that the start times are active.
Step 2: Check the Main Shutoff Valve
After winterization, your irrigation main shutoff valve was closed. It won’t open itself — you need to turn it back on manually. This valve is typically located:
- In the basement or utility room near the water meter
- In a ground-level valve box in the yard (green or black lid)
- Near the backflow preventer on the exterior of the house
Turn the valve slowly — opening it too fast can cause a water hammer that damages pipes. Open it about a quarter turn, wait 30 seconds, then open fully.
Step 3: Inspect the Backflow Preventer
The backflow preventer (also called a RPZ or double-check valve) is usually mounted on the exterior of your home or in a protective box. In winter, the test cocks on the backflow preventer are turned to 45 degrees to allow drainage. In spring, they need to be returned to their open (parallel to pipe) position before the system will flow water properly.
If the backflow preventer sustained freeze damage over winter (even if you winterized), it may not hold pressure and will need to be replaced before the system can run.
Step 4: Run Each Zone Manually
From the controller, manually activate each zone one at a time. Note which zones:
- Run normally — great, move on
- Show no water at heads — likely a failed solenoid valve or wiring issue
- Show very low pressure — possible broken pipe underground or a head that snapped off over winter
- Trip the controller with an error — usually a short circuit in the wiring, or a solenoid that shorted out
Common Reasons Sprinkler Systems Won’t Turn On in Spring
1. Solenoid Valve Failure
Solenoid valves are the electric valves that open and close each zone. They can fail from age, debris, or freeze damage. Symptoms: controller activates the zone but no water comes out. Replacement cost: $60–$150 per valve including labor.
2. Broken Lateral Line from Freeze
Even properly winterized systems can sometimes have a line that cracked if water pooled in a low spot. You’ll know this happened when a zone runs but you see a wet spot in the lawn, or one area is saturated while the heads elsewhere aren’t getting pressure. Repair: $150–$350 depending on depth and location.
3. Wiring Short or Break
Underground irrigation wiring can be damaged by lawn equipment, rodents, or settling soil. A shorted wire will often throw a fault code on the controller. Diagnosing wiring issues requires a multimeter and experience — this is usually a job for a tech.
4. Controller Programming Lost
If the controller battery died over winter, all schedules may have been erased. This is an easy fix — reprogram your start times, zone durations, and watering days. If you’re not sure how to do this, we include controller programming with every spring startup.
5. Rain Sensor Stuck
Rain sensors can freeze, swell, or get stuck in the “wet” position over winter, preventing the system from running. Most controllers have a bypass switch for the sensor — try bypassing it to see if the system runs. If it does, the sensor needs to be cleaned or replaced.
When to Call a Professional
Call us if:
- Multiple zones won’t activate and you’ve already checked the controller and shutoff valve
- You see water pooling in the yard (underground leak)
- The controller shows wiring error codes
- You can’t locate the main shutoff or backflow preventer
- The backflow preventer is dripping or won’t hold pressure
Our spring startup service includes a full system check, zone-by-zone test, head adjustment, and controller programming. We catch most problems before they become expensive mid-summer emergencies.
Schedule Your Spring Startup in South Jersey
Coastal Mist Irrigation handles spring startups across Ocean, Atlantic, Burlington, Monmouth, and Camden County. Call or text 609-548-5187 to book — April slots go fast.
NJ LIC#719827 | Licensed and insured irrigation specialists serving South Jersey since day one.