Turning on a residential irrigation system after a winter of dormancy requires a careful, methodical approach to avoid damaging the pipes and components. This annual spring startup involves a sequence of inspections, valve adjustments, and gradual pressurization to transition the system safely back to regular operation. Taking the time to perform these steps correctly can prevent leaks, premature component failure, and the costly repairs that result from sudden pressure surges.
Preparing the System for Water Flow
Before any water is introduced, a thorough visual inspection of the entire system is necessary to identify potential winter damage. Walk the property and check all visible components, including sprinkler heads, risers, and valve boxes, for cracks, displacement, or debris accumulation. Winter ground movement and freezing temperatures can cause physical damage, which must be noted for repair before the system is activated.
All drain valves and bleeder valves, which were likely opened during the winterization process, must be securely closed to hold pressure. Confirm that all individual zone valves are in the closed position, which prevents immediate flooding when the main water supply is turned on. Inside or near the home, ensure the irrigation controller has power restored and that the rain sensor is clear of any obstructions that could signal a false “rain event” to the system.
Activating the Main Water Supply
The process of introducing water into the system must be executed slowly to prevent “water hammer.” Water hammer is a powerful pressure wave created when water rushes into empty pipes too quickly, which can burst fittings and crack pipes. To begin, locate the main irrigation shut-off valve, often found near the water meter or where the line exits the house.
Open this main valve very slowly, using small increments, such as a quarter-turn at a time, and pause for approximately 30 seconds between turns. This gradual process allows the empty pipes to fill slowly, letting trapped air escape naturally without generating a pressure surge. The entire process of fully opening the main valve should take at least two minutes, ensuring the pipes are fully charged with water.
Once the main line is pressurized, the backflow prevention device, typically a Pressure Vacuum Breaker (PVB) or Reduced Pressure (RP) assembly, must be activated. If the device was removed for the winter, reattach it, ensuring the flow direction is correct. Slowly open the isolation valves on the backflow preventer, beginning with the valve closest to the water source. After the system is fully pressurized, perform an immediate visual check of the main lines and the backflow device for any major leaks before proceeding to zone testing.
Setting the Irrigation Schedule and Testing Zones
With the main lines charged and pressurized, attention shifts to the electronic controller and the final physical verification of the system’s operation. The controller must first be set to the current date and time for the programmed watering schedule to run accurately. Next, program the initial spring watering schedule, setting the start times, run times for each zone, and the watering days of the week.
It is beneficial to start with shorter run times in the spring, as cooler temperatures mean less evaporation compared to summer months. Once the programming is complete, manually activate each zone individually from the controller to begin the physical testing process. As each zone runs, observe for common issues such as leaks, heads that are stuck in the ground, or inadequate spray coverage.
During individual zone testing, confirm that the sprinkler heads are adjusted correctly, ensuring water is not being wasted on hard surfaces like sidewalks or driveways. If a zone fails to turn on, the issue may be electrical, such as a loose wire, or mechanical, like a malfunctioning solenoid at the valve box. Any sputtering or gurgling from the heads during the first minute of testing is normal, as the remaining air is expelled from the lateral lines.