Solenoid Control Valve Troubleshooting
| Symptom | Probable Cause | Remedy |
| Main valve fails to close | Too low pressure differential across valve (Need 5 psid min under flowing conditions) | Restrict valve opening with X102A flow limiting assembly. (Contact Factory) |
| Closed isolation valves in pilot system, or in main line | Open valves | |
| Diaphragm damaged | Replace diaphragm | |
| Mechanical obstruction | Remove obstruction | |
| Object lodged in valve. Worn disc. | Replace disc. Remove object. | |
| Badly scored seat. | Replace seat. | |
| CAN needle valve closed | Open this speed control to allow pressure to cover. | |
| Lack of cover chamber pressure | Check upstream pressure, tubing, needle valves for restriction. | |
| Main valve fails to open | Closed isolation valves in pilot system, or in main line | Open valves |
| Insufficient line pressure | Check pressure | |
| Diaphragm assembly inoperative | Clean & polish stem. Replace any defective or damaged parts. | |
| Main valve vibrates when closing | Air in cover | Bleed all air from valve cover. |
Click below for installation and maintenance sheets:
ZW106
Installation and Maintenance sheet 4" and smaller
ZW106
Installation and Maintenance sheet 6" and larger