Why Would a Sprinkler Head Weep?

Diagnosing the Problem

• A weeping sprinkler head will exhibit symptoms that no other sprinkler problem will. To determine whether your sprinkler head is truly weeping, run the sprinklers for several minutes and then shut them off at the timer. Watch sprinklers at various positions in the lawn. If water continues to run out of the heads for more than one minute, they are weeping heads. If the weeping stops before one minute, the residual pressure in the lines is simply bleeding out and is a normal part of the sprinkler operation.

Faulty Valves

• If your sprinklers continue to leak water one minute after the shutoff of the sprinkler system, a faulty sprinkler valve is probably to blame. In most cases, the diaphragm that holds the water back in the main line when the system is off has torn or is worn out. This small piece of thin plastic stretches over the inside of the valve and creates a vacuum that holds water back.

Faulty Diaphragm

• Another less common cause of weeping sprinkler heads is for the solenoid to be faulty or burned out. The solenoid is the black or gray object that attaches to the top or side of the valve. When activated by the sprinkler timer, the solenoid presses against the diaphragm to release the vacuum that holds the water back. If the solenoid is damaged, it may not retract fully and will cause the sprinkler heads to weep water.

Repairing a Weeping Sprinkler

• Whether a weeping sprinkler is caused by a faulty valve or solenoid, either can be replaced with a new unit. Some models of sprinkler valves have replacement diaphragm kits that are available at home improvement stores. These kits contain a new diaphragm that is installed by unscrewing the base of the valve, removing the old diaphragm and installing the new one. Solenoids also can be replaced by unscrewing the old unit and screwing in a new one. Replacement solenoids must match the pipe thread size of the old unit, so take the faulty unit to the hardware store for comparison.