Solenoid valves are mechanical devices, which means they are bound to fail over time. When that happens, immediate action is required to fix the problem. Luckily, these devices only have a few components. Solenoids valves also use relatively simple working mechanisms. As a result, they’re easy to service.
This article describes the ways to fix common solenoid valve problems using practical and straightforward troubleshooting methods. Read on to find out how.
Important! When servicing a solenoid coil, switch off the power to avoid causing it to burn out.
Problem: Solenoid Valve Not Opening
Possible causes include lack of power in the solenoid coil, burnt coil, wrong voltage, pressure differences (too high or too low), and dirt of the membrane, valve seat, or tube. It can also be due to a vital part of the solenoid valve missing or being damaged.
How to Fix Not Opening Solenoid Valve
Before attempting to fix the problem, determine the type of solenoid valve you have. It could be a normally open or normally closed solenoid valve.
Also, if it’s a directing acting or pilot operated type. That’s because failure of the valve to open can have different causes depending on the kind of valve.
1) Coil problem
Measure the voltage across the coil using a voltmeter. This should help you determine if the coil is working or not. You may also pull the coil slightly to feel if there’s a magnetic force acting on it. If it proves hard to pull, the coil is creating a magnetic field and, therefore, lasing current.
A burnt coil needs replacing.
2) Wrong voltage
For incorrect voltage, check to see that the supply matches the manufacturer specifications.
Solenoid voltage requirements vary. It can be a 12V solenoid valve or 24- volt solenoid valve DC and the wrong power supply could cause damage to the valve circuitry and coil.
AC voltages also vary from one solenoid valve to another. A 110- 120V solenoid valve should be used with a corresponding power supply.
Higher than that, and you may end up with a damaged valve.
3) Pressure differences
Solenoid valves have different pressure specifications. Check to see that the pressure across the ports does not exceed or go below that levels specified by the manufacturer.
If too high, reduce the input pressure. Pilot operated valves require certain minimum pressures to work.
If you find the pressure to be too low for the valve, consider replacing it with one whose pressure requirement matches that of the system.
4) Damaged, Dirty valve seat or seal, and Missing component
Clean the affected part to remove the dirt causing the component to jam. In case of damage, such as torn diaphragm for pilot solenoid valves, replace the affected part. Install a missing component.
Problem: Solenoid Valve Opening Partially
This problem can result from inadequate pressure, damaged components such as the armature and tube, dirt on the diaphragm, valve seat, or tube, corrosion, and missing parts. Solutions depend on the affected part or the type of fault.
How to Fix Solenoid Valve that Partially Opens
1) Low pressure
Ensure the pressure is high enough but within the manufacturer’s specified levels. An indirectly operated or pilot solenoid valve will not open fully if certain pressures levels are not attained.
2) Dirty, corroded, damaged, or missing parts
If the diaphragm, seat valve or tube are dirty, clean them. Replaced broken or damaged components.
Corroded parts may not function as required and should be replaced. Install missing components, too.
Problem: Solenoid Valve Not Opening or Opening Partially
Among the causes of this solenoid valve problem are coil issues, dirt or damage in the moving parts such as membrane or tube, pressure differential or pulsating pressure, damaged armature and valve seal, missing parts, or simply wrong installation.
How to Fix Solenoid Valve Not Opening or Opening Partially
- Coil problem
Pull at the coil to feel if there’s the resistance caused by a magnetic field. If it doesn’t offer resistance, there’s little or no current flowing.
You may need to check the connections or replace the coil.
2) Dirt in moving components
clean the solenoid valve diaphragm, valve seat, and plunger tube. Replace any of these parts that’s broken or damaged by corrosion.
3) Pressure problems
Check the valve pressure specifications against those of the source or medium. If they’re way different (medium flow rate either too high or too low), consider installing a new solenoid valve with the right specifications
4) Missing Parts and Wrong Installation
Re-install components that you find to have been placed incorrectly and replace the missing ones.
Problem: Solenoid Valve Making Buzzing or Water Hammer Noise
Water hammer or thumping sounds may indicate pressure differences in the ports. It could also be that the flow of the medium is pulsating.
Buzzing sound is often a normal occurrence when alternating current flows in the coil windings. In some instances, the surrounding parts of the valve pick up the noise and cause it to amplify.
How to Fix Solenoid Valve Water Hammer Noise
Reduce the media speed by increasing the diameter of the piping. You can also use a slow acting valve such as a ball valve.
That’s is because water hammer often results from valves with short response times. Alternatively, you can utilize a water hammer arrestor to reduce the noise.
How to Fix Buzzing Sound in Solenoid Valve
It can be caused by loose components resonating to the low hum of the solenoid coil. Tightening the parts can reduce the noise to some degree.
If the loud hum or buzz doesn’t subside, use a rectifier unit in the valve circuitry to correct the alternating current noise.
If the accompanied Noise is cause by Pressure Problem
Make sure the manufacturer specifications match the flow rate of the medium or the source pressures. Incompatibility is often the issue, and which can only be corrected by installing the right solenoid valve.
Problem: Burnt Coil
There are several causes of burnt coil in a solenoid valve. They include wrong voltage, a short circuit, dirt or damage in the moving parts such as the plunger, and media that’s too hot. Some coil types are more prone to burning and the problem could have been caused by the wrong choice.
How to Fix Burnt Coil
1) Incorrect voltage
Check the solenoid valve coil voltage specifications and those of the power supply. If incompatible change the coil and use one whose voltage requirements are in line with your power source.
Solenoid valve voltages vary across different valve types and sizes. Ensure you install the right one for your situation.
2) Short circuit
Inspect the solenoid valve wiring. Test for voltage variations. Correct any fault in the wiring system or solenoid valve circuitry.
Check the valve for fluid leaks that could have caused shorting of the circuits. Fluid or moisture is one of the causes of short circuits that cause solenoid valve problems.
3) Dirt or bent moving parts
Clean the plunger assembly, the tube especially. The dirt on these components could be causing immense friction and high temperatures when the valve is operating.
If any of these parts is broken or bent, replace them.
4) High medium or surrounding temperature
If the coil has burned out due to the fluid being too hot, you may need to replace the valve with a type that can withstand high temperatures. Consider dealing with the temperature surrounding the installation if too high.
Another remedy would be to increase the ventilation of the area where the valve is installed.
A faulty solenoid valve cannot operate according to requirements.
It may not regulate the medium in the system well, which can lead to fluid leaking through the orifice.
If the valve’s function is to dose or mix liquid, it can be a disastrous situation.
The same case if the valve controls functions where accuracy is paramount.
Knowing how to find out about the solenoid valve problems and how to correct them can help avert unwanted system issues.