Common Solenoid Valve Issues and Fixes

Solenoid valves are crucial in pneumatic and hydraulic systems because they control the flow of fluids and gasses, ensuring proper operation and functionality. While relatively simple, they can encounter issues like not opening/closing properly, leaking, or overheating. Another common issue is a too-low differential pressure for indirect operated solenoid valves. These issues often stem from debris, damaged parts, or electrical problems. Fixes include cleaning, replacing damaged components, and repairing electrical or cooling systems.

Solenoid valve troubleshooting

This section provides comprehensive guidance on how to troubleshoot the following common solenoid problems:

• The solenoid valve does not open
• The solenoid valve opens partially
• The solenoid valve makes a humming noise
• The solenoid coil is burnt

Solenoid valve does not open

Probable cause	Solution
No power to the coil	Check if the valve is normally open (closes when electrically energized) or normally closed (opens when electrically energized). Measure the voltage across the coil with the aid of a voltmeter or multimeter. Ensure voltage across the coil matches its required specifications. Pull the coil up a little and feel if the coil produces resistance to displacement (magnetic field). Note: Removing a powered coil may cause the coil to burn. Check the relay contacts, wires and fuses.
Incorrect voltage/frequency	Make sure the power supply matches the valve specification. Measure the voltage across the coil.
The coil is burnt	See the section below about burnt coils.
Differential pressure is too high	Check the pressure differential across the valve using two separate pressure gauges or a differential pressure gauge. Compare the differential with the valve specification. If possible, you can make the pressure difference smaller, for example by reducing the input pressure.
Differential pressure is too low	Check the valve specification. Indirect controlled solenoid valves need a small differential pressure to operate properly. If necessary, replace the solenoid valve for a suitable alternative, such as a (semi) direct operated solenoid valve.
Damaged or deformed valve	Replace the solenoid valve
Dirt on the membrane	Clean the membrane. If necessary, replace broken or damaged components.
Polluted valve seat or valve	Clean the valve. If necessary, replace broken or damaged components.
Corrosion (rust)	Replace damaged components
Components missing after disassembly	Install the missing components

The solenoid valve opens partially

Probable cause	Solution
Pressure too low	Check the valve specification for the minimum differential pressure. Indirectly controlled solenoid valves require a small differential pressure for proper operation. Replace the valve with a type that operates from 0 bar, such as a (semi) direct operated solenoid valve or an electric ball valve.
Damaged or bent armature tube	Replace the valve
Dirt on the membrane	Clean the membrane and, if necessary, replace the broken parts
Dirt in the valve seat/valve/pipe fittings	Clean the valve, if necessary, replace broken parts
Corrosion	Replace defective parts
Part missing after the assembly	Replace the missing parts

The solenoid valve makes a humming noise

Probable cause	Solution
Buzzing	AC coils can cause a humming noise, which can get louder if nearby parts vibrate at the same frequency. Securing these parts can reduce the noise. Installing a rectifier, like a power saver module, can also solve the buzzing problem.
Water hammer	Increase the pipe diameter to reduce the fluid velocity. Reduce the pressure with a pressure-reducing valve before the solenoid valve. Dampen the water hammer by using a flexible hose or buffer before the solenoid valve. Use a solenoid valve with a longer response time. This reduces the pressure transients.
Differential pressure too high and/or pulsation in input line	Check valve specification and differential pressure. Check pressure and flow. Replace with a suitable valve. Check out the rest of the installation.

Coil is burnt

Probable cause	Solution
Incorrect voltage/frequency	Check the coil specification. If necessary, replace it with an appropriate type of coil. Check the wiring diagram. Check the voltage variations.
Coil short circuit (possibly fluid)	Check the rest of the installation for possible short circuits. Check the connections of the coil. Replace the coil when the error is found. Note the installation of the coil, make sure that no moisture can flow or drip in the connection.
The plunger moves with high friction (by dirt, damage or bending)	Replace broken parts and remove dirt
The temperature of the medium is too high.	Check the valve specification. If necessary, replace the valve with a suitable variant.
The ambient temperature is too high.	If possible, move the valve to a cooler environment. Check the valve specification. Increase ventilation around the coil and valve.

FAQs

How to fix a stuck solenoid valve

To fix a stuck solenoid valve, first, ensure power is off. Check for debris and clean. Inspect and lubricate the plunger. Verify electrical connections and correct voltage. Replace damaged parts.

What are common solenoid valve issues?

Common solenoid valve issues include not opening/closing properly, leaking, overheating, and low differential pressure for indirect operated valves.

What causes a solenoid valve to get stuck?

A solenoid valve can get stuck due to debris, corrosion, damaged internal components, or electrical issues.