Isolating a single sprinkler head is common in residential irrigation systems, often needed for localized repair, water conservation, or landscaping changes. Stopping flow to one head without deactivating the entire zone allows the rest of the system to continue operating normally. Successfully turning off one head requires understanding the system’s components and selecting the appropriate method for a short-term or permanent solution.
Preparation and Safety Before Starting Work
Before starting work, the water supply to the specific irrigation zone must be completely shut off. Locating the zone valve and turning off the water depressurizes the line, preventing an unexpected surge when the head is removed. Skipping this step can lead to a significant water plume.
After turning off the supply, briefly activate the zone to relieve any residual pressure trapped within the lateral line. Gather necessary tools, including a small shovel or trowel, a wrench or channel locks, and rags. For threaded connections, polytetrafluoroethylene (PTFE) tape, also known as Teflon tape, is needed to ensure a watertight seal.
Excavate the ground around the sprinkler head, creating a working area about six inches deep and eight inches in diameter. This exposes the riser—the vertical pipe connecting the head to the underground lateral line. Keeping the excavated soil on a tarp or in a bucket helps maintain a clean workspace and simplifies backfilling later.
Temporary Method: Sealing the Riser
The simplest way to stop flow is by sealing the connection point at the riser. This approach is ideal for short-term fixes, such as during a temporary landscaping project or while waiting for a replacement part. One option involves removing the entire sprinkler body from the riser and installing a threaded PVC cap directly onto the exposed riser threads.
The cap must be correctly sized to match the riser connection, typically half-inch for spray heads or three-quarter-inch for rotor heads. Wrap the threads with PTFE tape before screwing on the cap to create a seal that resists leakage. This method plugs the outlet, but the empty sprinkler body must be stored until the head is needed again.
A less invasive technique uses specialized shut-off nozzles or plugs designed to fit into the head assembly. These plastic inserts replace the existing spray nozzle, blocking the flow of water. This allows the sprinkler body to remain in place, preserving its visibility if the head will be reactivated soon. Once installed, briefly test the system for leaks before backfilling the hole.
Permanent Method: Removing and Plugging the Line
A permanent solution is necessary when the sprinkler head is removed indefinitely, such as due to a change in garden design or a new patio. This method requires removing the entire riser and sealing the connection point on the underground lateral line. Begin by digging down to expose the “T” or elbow fitting where the riser connects to the main supply pipe.
Once the fitting is visible, unscrew the riser pipe from the connector, leaving a threaded opening in the lateral line. For rigid PVC pipe systems, this opening is typically half-inch or three-quarter-inch female threads. Wrap a corresponding male-threaded PVC plug with sealant or PTFE tape and securely screw it into the fitting.
For systems using flexible polyethylene (poly) pipe, the connector is often a barbed fitting or a saddle tee. In this case, the entire connector must be removed. The hole in the poly pipe must then be sealed using a specialized repair coupling or a figure-eight clamp. After installation, run the zone for a full cycle to confirm the connection holds pressure before backfilling the trench.