If some zones on your sprinkler system aren’t turning on, it usually points to electrical, valve, or controller issues. Here’s a quick breakdown to help you troubleshoot like a pro:

Wiring or Solenoid Problems

Each zone is controlled by a solenoid valve that opens when it gets an electrical signal.

Loose, corroded, or broken wires = no signal

A bad solenoid = the valve won’t open

Fix it:

Check wiring connections at the controller and valve box

Use a multimeter to test for voltage (typically 24V AC)

Replace the solenoid if it’s not responding

Faulty Valve

Sometimes the valve itself is clogged or stuck closed due to:

Debris

Mineral buildup

Mechanical failure

Fix it:

Manually open the valve to see if water flows

If it works manually but not electrically, likely a solenoid issue

If it doesn’t work manually, the valve may need cleaning or replacing

Controller/Timer Issue

The controller might not be sending the signal due to:

Programming error

Zone turned off in settings

Blown fuse or internal fault

Fix it:

Double-check your schedule and zone settings

Reset the controller if needed

Try manually starting the affected zone from the controller

Low Water Pressure or Supply Issue

If the water supply to the system is low or a main valve is partially closed, some zones might not activate.

Fix it:

Make sure the main shutoff valve is fully open

Check for leaks or pressure issues upstream

Quick test tip:

Try manually starting each zone at the controller. If a zone won’t start but others do:

Likely a valve or wire issue
If no zones work:

Likely a controller or mainline problem