The plunger is the small, metal piston with a rubber base inside the solenoid housing. The plunger must be clean and free of any debris. To check the operation of the solenoid, manually turn on the valve or zone from the irrigation controller.
Valves. When troubleshooting an electronic solenoid valve, it is important to quickly isolate the problem as either electrical or hydraulic. Electric solenoid valves are powered by 24 volts AC (VAC) from the irrigation controller. The most common symptoms of electrical problems are valves failing to turn on.
When a solenoid valve (also called an electric valve or automatic sprinkler valve). When a valve fails to open it is usually due to a bad solenoid or bad wiring, .
If the valve won't open at all, or doesn't fully open, start with the obvious. Once I had a system I couldn't get to work, couldn't find any closed valves, but still no water to the sprinklers.. The problem is with the valve or the valve solenoid.