Possible cause |
Solution |
No voltage on coil |
Check whether the valve is open or closed de-energized (NO or NC): |
Incorrect voltage / frequency |
Check that electrical requirements for the coil are the same as power supply. Measure voltage on the coil. Permitted voltage deviations: +/- 10% for dual frequency; Applications with direct current and NO + 10% / - 15% for alternating current, single-frequency voltage. If necessary, replace the coil with the correct version. |
Differential pressure too high |
Check the coil info. If necessary, replace the coil with the correct one. Reduce the differential pressure, for example by reducing the inlet pressure. |
Differential pressure too low |
Check the coil info including the differential pressure. If necessary, replace the coil with the correct one. |
Damaged or bent tube |
Replace the valve. |
Impurities on the diaphragm |
Clean the diaphragm. If necessary, replace defective components. |
Dirt in the armature or in the tube |
Clean the valve. If necessary, replace defective components. |
Corrosion |
Replace defective components |
Missing components after valve removal |
Supply missing components |
Possible cause |
Solution |
Differential pressure too low |
Check the coil info including the differential pressure. If necessary, replace the coil with the correct one. |
Damaged or bent tube |
Replace the valve. |
Impurities on the diaphragm |
Clean the diaphragm. If necessary, replace defective components. |
Dirt in the armature or in the tube |
Clean the valve. If necessary, replace defective components. |
Corrosion |
Replace defective components. |
Missing components after valve removal |
Supply missing components. |
Possible cause |
Solution |
Humming |
Humming caused by alternating current frequency. It can be removed by replacing it with a rectifier coil. |
Hydraulic shocks when opening the valve / Hydraulic shocks when closing the valve |
Hydraulic shock is a typical result of high fluid velocity. There are several solutions to this problem: 1. Pressure reduction by installing a pressure reducing valve in front of the solenoid valve. If possible, increase the tube diameter. 2. Reduction of hydraulic shock by installing a flexible hose or flexible bumper in front of the solenoid valve |
Differential pressure is too high / pulsation in the pressure line |
Check valve info, incl. differential pressure. Check fluid pressure and flow. Replace the valve with a more suitable type of valve. Check other installation components. |
Possible cause |
Solution |
Voltage remains on the coil |
First, lift the coil slightly to see if it resists. Note: The coil must not be removed under voltage, otherwise it could burn out. Check the wiring according to the wiring diagram. Check relay contacts. Check the wire connections. |
Dirt in the orifice / leveling nozzle |
Clean it with a needle or similar object (max. Diameter 0.5 mm). Blow out the hole with compressed air. If necessary, replace defective components. |
The manual opening unit cannot be screwed back on after use |
Check the position and adjust it as required. |
Pulsation in the pressure pipe. The differential pressure is too high in the open position. The pressure on the outlet side is periodically higher than the pressure on the inlet side. |
Check valve info. Check fluid pressure and flow. Replace the valve with a more suitable type of valve. Check other installation components. |
Damaged or bent armature tube |
Replace the valve. |
Defective valve spring, diaphragm or valve plunger. |
Check fluid pressure and flow. Replace the defective components. |
Diaphragm in inverted position |
Check that the valve is installed correctly. |
Dirt in the armature or in the tube |
Clean the valve. If necessary, replace defective components. |
Corrosion in the orifice |
Replace defective components. |
Valve incorrectly mounted |
Check the direction of fluid flow and make sure the arrow is pointing in the same direction. |
Missing components after valve removal |
Supply missing components. |
Possible cause |
Solution |
Incorrect voltage / frequency |
Check the coil data. If necessary, replace the coil with the correct type. Check the wiring according to the wiring diagram. Check the maximum voltage deviations. Voltage tolerances: +/- 10% for dual frequency, DC applications, +10% or -15% for AC, single frequency voltage |
Coil shorted (there may be moisture in the coil) |
Check other components for possible short circuits. Check the connection of the wires to the coil. When a fault is found, replace the coil. Consider mounting a snap-on coil with an additional O-ring body seal (only for the high-performance range of valves). |
Prolonged flow through the valve 1) Damaged or bent tube 2) Damaged armature 3) Dirt in the armature tube |
Replace defective components. Clean dirt. |
Medium temperature too high |
Check that the valve and coil data match the installation parameters. Replace with a suitable type of coil or valve. |
Temperature too high around the valve |
If possible, move the valve to a cooler place. Check that the valve and coil data match the installation parameters. Increase ventilation around the valve and coil. |