Two of the most common problems with a sprinkler valve are a failed solenoid (valve won’t turn on) and debris in the valve or damage to the valve diaphragm (valve won’t turn off).
Valve Not Turning On
When a sprinkler valve is not turning on, it can be due to an electrical problem, a water supply issue, or a failed solenoid. A good place to start is by ruling out a water supply problem. To do this, check the other sprinkler valves to ensure they are getting water and turning on as usual. If none of the valves comes on, it suggests that the water shutoff valve to the entire sprinkler system may be the issue. For example, the problem might be that the water source is turned off and just needs to be turned back on. If only one valve is not turning on, check to see if it will turn on manually. Many valves have a switch or lever on the valve itself that allows you to activate the valve without electricity. If the valve works when activated manually, the problem is likely due to a bad wire connection or a bad solenoid on the valve. Check the wires first. Make sure there is good contact at the point where the system wires connect to the solenoid wires and that there are no cuts or breaks in the wires. If the wires look fine, move on to the next step: replacing the solenoid.
How to Replace a Valve Solenoid
Replacing the solenoid is an easy sprinkler valve repair. Home centers and sprinkler equipment suppliers carry replacement solenoids for specific valve brands and models. To ensure an exact match, bring the old solenoid with you to the store.
Valve Not Turning Off
When a sprinkler valve is not turning off it may be due to debris inside the valve or because the diaphragm (rubber gasket) inside the valve is damaged. If the diaphragm is torn or damaged, it will not be able to stop all of the water so the sprinklers will not turn off. Rebuilding is a fairly common sprinkler valve repair, and rebuild kits that include a replacement diaphragm are available for many valves. It is a good idea to have a rebuild kit ready before opening the valve, just in case the diaphragm needs replacement.
