How To Turn The Sprinkler System On Safely And Efficiently
Operating an irrigation system requires balancing water pressure, timing the automated controller, and manually priming the main supply line to prevent water hammer and catastrophic pipe blowouts. By methodically opening the backflow preventer, charging the main manifold, and running a manual station test, you ensure even lawn coverage while protecting your infrastructure from thermal and hydraulic shock.
Pre-Operation & Equipment Checklist
Activating an irrigation network after a seasonal shutdown or installation phase requires methodical planning to prevent excessive static water pressure from cracking fittings. Neglecting the sequence of valve openings can send a high-velocity water slug through empty PVC or poly pipes, leading to shattered joints and underground leaks.
- Essential Gear and Tools: Channel-lock pliers, a flathead screwdriver for manual bleed screws, plumber's tape (PTFE) for emergency thread sealing, and a flashlight for dark utility boxes or basements.
- Mandatory Prerequisite Knowledge: Familiarity with the main water shutoff valve location, understanding of the backflow preventer assembly (specifically Ball Valve 1 and Ball Valve 2), and basic operation of the digital irrigation controller or timer.
- Time and Budget Benchmarks: The entire activation process takes approximately 15 to 30 minutes. If components require replacement due to frost damage, parts costs generally range from twenty to one hundred dollars.
Step-by-Step Irrigation Activation Workflow
Step 1: Inspect the System and Close All Manual Drains
Begin your activation sequence by conducting a comprehensive visual walkthrough of the property to verify that all winterization drain valves, petcocks, and low-point caps are completely closed and securely tightened. Leaving a single manual drain open will cause a massive pressure drop, preventing downstream zone valves from opening correctly and flooding the immediate soil around the drain point. Check all exposed above-ground piping, especially around the backflow preventer and pump housing, for cracks or loose fittings before introducing water.
Step 2: Open the Main Water Supply Slowly
Locate your main irrigation supply line, which typically branches off the domestic water meter or a dedicated sub-meter, and prepare to introduce water. Turn the main isolation valve or curb stop handle counter-clockwise or parallel to the pipe (depending on whether you have a ball valve or a gate valve) by only about 25 percent. Listen carefully for the sound of rushing water filling the dry main line; this slow introduction prevents a destructive water hammer effect. Once the sound of rushing water stops—indicating the lines have filled to static pressure—slowly rotate the valve until it is fully open.
Step 3: Engage the Backflow Preventer Assembly
The backflow preventer (such as a Pressure Vacuum Breaker or Double Check Valve) protects your potable drinking water from cross-contamination and must be pressurized in the correct sequence. Locate the two primary shutoff valves on the backflow device, designated as Valve 1 (upstream, coming from the main supply) and Valve 2 (downstream, leading to the zone valves). Open Valve 1 slowly first, allowing water to enter the assembly and fill the test cocks. Next, open Valve 2 slowly to allow water to charge the downstream lateral lines up to the automatic zone valves.
Warning: Opening the backflow preventer valves too quickly can force trapped air through the system at high velocity, shattering brittle plastic components or dislodging internal check valve seals.
Step 4: Program and Test the Irrigation Controller
Navigate to your automated indoor or outdoor irrigation controller and turn the dial from the "Off" or "Rain Delay" position to the "Run" or "Auto" setting. Review the current time, date,ing schedule, and watering run times to ensure they comply with local municipal watering restrictions. Initiate a manual zone test by selecting the "Manual Run All Stations" or "Test" feature, setting a run time of two minutes per zone. Walk your property as each zone activates to visually inspect sprinkler heads for proper arc rotation, missing nozzles, broken risers, or excessive pooling around the head bodies.
Manually Turning On Sprinkler Valves
Irrigation Component and Pressure Specifications
| Component Parameter | Standard Rating / Specification | Operational Threshold | Common Failure Mode |
|---|---|---|---|
| Static Water Pressure | 40 to 65 PSI (Pounds per Square Inch) | Max 80 PSI before requiring a pressure regulator | Head blowouts, pipe joint leaks |
| Backflow Preventer | Pressure Vacuum Breaker (PVB) or RPZ | Must be installed 12 inches above highest head | Bonnet freezing, internal seal cracking |
| Lateral Pipe Material | Schedule 40 PVC or SDR-21/SDR-26 Polyethylene | Rated for continuous working pressure of 160 PSI | Split walls from residual ice expansion |
| Solenoid Valves | 24-Volt AC (Alternating Current) | Operates on minimal electrical resistance (20-60 ohms) | Diaphragm debris fouling, electrical shorting |
Troubleshooting Common System Activation Failures
- Root Cause: The main controller screen is completely blank and unresponsive when attempting to run a manual test.
- Action الغذant Fix: Check the primary electrical outlet or transformer plug to ensure uninterrupted power. Inspect the internal 1-amp or 3-amp fuse inside the controller housing and replace it with an identical amperage fuse if blown.
- Root Cause: A specific zone fails to turn on when manually activated from the controller, while all other zones function normally.
- Action Fix: Test the zone's corresponding solenoid wiring with a multimeter for continuity. If electrical signals are verified, manually twist the solenoid bleed screw counter-clockwise to check if manual water flow forces the valve open, indicating a faulty electrical solenoid requiring replacement.
- Root Cause: Sprinkler heads in a specific zone pop up, but water only trickles out with insufficient distance and coverage.
- Action Fix: Inspect the inline filter or screen inside the individual sprinkler head body for sand, dirt, or pipe debris accumulation. Unscrew the riser assembly, flush the lateral line briefly with the nozzle removed, and clear the obstruction.
Frequently Asked Questions
Which backflow valve should be opened first when turning on the system?
You must always open the upstream valve (the valve closest to the main water supply line) first to slowly pressurize the backflow assembly. Once the device housing fills and stabilizes under pressure, you can slowly open the downstream valve to allow water into the rest of the underground lateral lines.
What causes a loud banging sound in the pipes when I turn on the sprinklers?
This phenomenon is known as water hammer, caused by a high-velocity column of water abruptly stopping or rushing into empty, unpressurized pipes. To eliminate this issue, ensure you open your main supply valves only a quarter of the way initially to let air bleed out and lines fill gradually.
Do I need to turn off my sprinkler system during heavy rain?
Yes, running your irrigation system during or immediately after heavy rainfall wastes water and can saturate your landscape, leading to root rot and fungal diseases. Most modern controllers support a hard-wired rain sensor or a smart Wi-Fi weather module that automatically suspends cycles based on local precipitation data.
Can I turn my sprinkler system on if the backflow preventer is leaking?
No, you should never leave a leaking backflow preventer pressurized, as it indicates cracked brass or frozen internal check valves that violate municipal cross-connection codes. Shut off the water supply immediately, replace the damaged components or bonnet assembly, and re-test the device before running automated cycles.
Ready to optimize your landscape irrigation for maximum water efficiency and vibrant turf health? Contact our certified irrigation specialists today for comprehensive system audits, backflow testing, and smart controller upgrades tailored to your property.
