– Damaged piston seal or piston assembly
• Replace valve assembly
Valve won’t close (Hydraulic)
– Leak in control tubing
• Isolate and repair
– Pilot valve leak in controller
• Confirm by observing constant dripping from discharge line of controller. Refer to Controller Service Manual
– Valve cylinder misaligned with sprinkler body communication tube
• Remove valve assembly and install correctly
– Foreign object keeping valve from seating
• Remove, clean and check valve for damage. Replace if necessary
– Damaged piston seal or piston assembly
• Replace valve assembly
Valve won’t open (Electric)
– Control (field) wires severed
• Isolate and repair
– No power to controller
• Establish controller power
– No power from controller to solenoid
• Check for blown fuse and replace
– Manual control selector on pilot valve assembly turned to “OFF” position
• Turn to “AUTO” position
– Pilot valve solenoid inoperative
• Remove and replace
– Pilot valve plunger movement restricted
• Inspect, clean and/or replace
– No supply from main valve
• Debris in control tube, main valve assembly and/or communication passages in body. Flush thoroughly
Valve won’t open (Hydraulic)
– Plugged controller discharge line or discharge port in pilot valve
• Verify by checking for discharge at discharge line when station is activated. If no discharge, refer to
Controller Service Manual
Sprinkler Weeping (Slow leak in valve)
– Damaged or blocked valve seat
• Remove blockage and, if necessary, replace valve assembly
– Damaged piston seal or piston assembly
• Replace valve assembly
– Damaged pilot valve discharge seat
• Clean or replace pilot valve
– Damaged pilot valve plunger
• Clean or replace plunger
– Low pressure on supply line (N.O. Hydraulic Models)
• Check for low pressure reason and correct
– Elevation of normally closed sprinkler exceeds 75' (22.9 m) differential
Several valves on different stations fail to close (Hydraulic)
– Control tubing leak which lowers supply pressure to other stations
• Turn controller from station to station until a station is reached where only valves on that station stay open
The leak would be in the tubing on that station. Isolate and repair
– Leak in supply line to controller
• Verify by checking pressure in all control lines
– Leak in controller pilot valve
• Verify by constant discharge from controller
– Plugged supply line filter
• Replace filter if more than 3 psi (0.21 bar) differential exists
Servicing Procedures
The FLX35-6 and FLX55-6 series sprinklers are designed to provide the user trouble-free operation for many years
without scheduled maintenance. If it becomes necessary to disassemble the sprinkler to correct a malfunction or
replace a component, all internal parts of the sprinkler can be accessed from the top. Refer to the Troubleshooting
Procedure in this manual in the event of a malfunction. Some special tools are required for disassembly and/or
maintenance of the sprinkler and are available from your Toro dealer.
