Before You Begin

An in-ground lawn sprinkler system consists of several components.

A water supply pipe from the main water source will first pass into a valve box at ground level.

From there, it’s divided into individual underground irrigation zones, each controlled by its ownzone valve.

Lawn irrigation sprinkler spraying water across various lawn plants, pathway lamp and sidewalk

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Most homes have at least two or three irrigation zones, but some smaller homes may only have one.

The solenoid controls a spring-loaded metal piston that opens or closes the water port passing through the valve.

Some irrigation zone valve models may also integrate ananti-siphon unit.

Materials and tools to troubleshoot lawn irrigation system

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Run a single zone for a few minutes while you look for problems with the system.

Find the Issue

First, confirm if a broken sprinkler head is the problem.

There are several possible causes and solutions.

Sprinkler head not popping up from ground

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This shows where you oughta dig down and repair thewater line.

Sometimesbut more rarelythis can be triggered by a faulty valve that needs to be rebuilt or replaced.

Inspect the Valve Solenoid

The solenoid on the valve may be faulty and need replacing.

Clearing soil area around sprinkler head closeup

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Screw on a new solenoid, and reconnect the wires.

Check the Sprinkler Valve

The valve itself may need to be cleaned or replaced.

In some cases, simply disassembling and cleaning the diaphragm will solve the problem.

Individual sprinkler head being replaced and inserting into riser tube

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In other cases, replacing the diaphragm and spring will be the fix.

In more severe cases,replacing the entire valvewill be the solution.

Use a multimeter to test the wire terminals marked “24-vac.”

Water valves on backflow device checked for low water pressure

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If the reading is below 22 volts, replace the transformer.

In this case, disassemble and rebuild the valve with a new diaphragm.

Check the Zone Valve

A cracked valve body could be the cause leaking.

Underground irrigation water line pipe checked for leaks

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In this circumstance, call a professional to help replace the zone valve.

Inspect the head and correct any problems you find.

Rebuild the Zone Valve

A worn-out or damaged zone valve can also cause this issue.

Irrigation water line pipe compressed underground

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It may be a sign that the valve is failing to close completely.

Dissemble, clean, and rebuild the valve.

If this does not solve the problem, thevalve may need to be replaced.

Voltage on sprinkler terminal being check for single zone not turning on

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Check the valve to double-check the flow direction is correct.

However, there are some instances where it’s safer to call a pro.

Low-voltage wires from the controller being checked to turn on single zone

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Valve solenoid being inspected for single zone not turning on

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Sprinkler valve inspected for single zone not turning on

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Transformer being tested for low-voltage power in multiple zones

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Screwss on anti-siphon device tightened with screwdriver

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New diaphragm installed inside the valve

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Zone valve body checked for cracks to cause leaking

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Sprinkler head checked for cleaning or replacement

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Damaged zone valve inspected for replacement

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Direction of water flow in zone valve being checked

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