How Does a Solenoid Valve Work?
Solenoid valves play a crucial role in a wide range of home appliance. Whether used in a washing machine or a dryer, solenoid valves offer precise control over the flow of liquids and gases, making them essential for automation and fluid management.
But how do these small, efficient devices work? Let’s dive into the mechanics, operation, and common applications of solenoid valves to uncover their significance and versatility.
KEY TAKEAWAYS
- Solenoid valves are used in many household appliances, including washing machines, dishwashers, refrigerators, and gas dryers, allowing for accurate control of water, gas, and other fluids essential to appliance functions.
- Solenoid valves operate through an electric coil that creates a magnetic field when energized, moving a plunger to control fluid or gas flow. This simple yet effective mechanism enables quick and reliable on/off flow control.
- Keeping appliances well-maintained, including cleaning and professional inspections, can help prevent solenoid valve issues. This maintenance extends appliance life, preventing problems like water fill failures, leaks, or heating issues.
What is a Solenoid Valve?
A solenoid valve is an electromechanically operated valve that controls the flow of liquid or gas through a system.
The valve is operated by an electric coil called a solenoid, which, when energized, creates a magnetic field. This magnetic field moves a plunger or armature inside the valve, opening or closing the passage for fluid or gas flow.
Solenoid valves are often preferred in automated systems for their reliability, quick response, and precise control.
Basic Components of a Solenoid Valve
Understanding the working of a solenoid valve requires a closer look at its key components:
- Solenoid Coil: This is an electromagnetic coil that generates a magnetic field when an electric current passes through it.
- Plunger or Armature: A movable metal component, typically iron or stainless steel, that reacts to the magnetic field generated by the solenoid. It either opens or closes the valve.
- Valve Body: The outer casing of the valve, usually made of metal or plastic, which encloses the fluid or gas passage and protects the internal parts.
- Inlet and Outlet Ports: Openings through which the fluid or gas enters and exits the valve.
- Spring: A spring is often used to push the plunger back to its original position when the solenoid is de-energized.
How Does a Solenoid Valve Work?
The operation of a solenoid valve can be understood in two phases: energized (when electric current is applied) and de-energized (when electric current is removed).
1. Energized State (Valve Opens)
When the solenoid coil is energized, it creates a magnetic field that pulls the plunger or armature away from the valve seat. This movement opens the valve, allowing the fluid or gas to flow through the inlet and out through the outlet.
2. De-Energized State (Valve Closes)
When the electric current is cut off, the magnetic field collapses, and the spring pushes the plunger back to its original position, which closes the valve. In this state, the fluid or gas flow is stopped, or redirected, depending on the specific valve design.
Applications of Solenoid Valves in Home Appliances and Troubleshooting Tips
Thanks to their versatility and reliability, solenoid valves are found in an extensive variety of appliance applications. Here are some examples of appliances that use solenoid valves and how to troubleshoot common problems.
Washing Machines
Washers use at least 2 solenoid water valves (hot & cold) to fill the washer tub. Many front-load washers and some top-load models have additional water valves for dispensing detergent and other cleaning media such as bleach and fabric softener.
The electronic control or timer provides power to open the valves and fill the washer as well as dispense additives at various times during the cycle.
In some washers – mainly top-load washers, the water level pressure switch shuts off current to the solenoid fill valves to stop the filling process and advance the wash or rinse cycle.
If you have a top-load washer that won’t fill, follow the DIY troubleshooting steps in this video to find and fix the problem:
If you’re unable to find and fix the cause of a fill problem in your washing machine, schedule washer repair service and we’ll send a Sears Home Services technician to your home to fix the fill problem for you.
Dishwashers
A dishwasher uses a single solenoid water valve to fill its tub with water. The electronic control board or timer on a dishwasher controls electronic current going to the fill valve.
Most dishwashers use an overfill float switch to shut off electric current going to the fill valve to prevent overfilling the tub.
While a failed solenoid valve can prevent a dishwasher from filling, you’ll need to properly diagnose the cause of a dishwasher fill failure because other components could be causing the problem. Here’s a DIY troubleshooting video that shows how to fix a fill problem in the most common types of dishwashers:
If you’re unable to find and fix the cause of a dishwasher fail failure, schedule dishwasher repair service to have a Sears Home Services tech resolve the issue for you.
Refrigerators
Many refrigerators have ice makers and water dispensers that use solenoid water valves to control water flow to these components.
The control system for these valves vary. The ice maker module, water dispenser switch and/or electronic control boards control the activation of water valves to supply water to the ice maker and water dispenser.
When your refrigerator isn’t getting water, follow the tips in our How to diagnose a faulty refrigerator water inlet valve article to find and fix the cause of the problem. As always, if you’re unable to resolve a water supply problem with your fridge on your own, schedule service to have a technician fix the issue.
Gas Clothes Dryers
Gas dryers use solenoid gas valves connected in a safety circuit with a flame sensor to supply the burner with natural gas or Propane gas. Failed solenoid valve coils are a leading cause of heating problems in gas dryers.
Here’s a DIY troubleshooting video that explains how solenoid gas valves operate in a clothes dryer and how to fix a heating problem in that appliance:
Replace the solenoid gas valve coils if they’re too weak to open the gas valves to heat the dryer.
If you’re unable to find and fix a heating problem in your dryer on your own, schedule dryer repair service and we’ll resolve the heating issue for you.
Maintaining Your Appliances to Prevent Solenoid Valve Problems
To prevent the appliance failures caused by failed solenoid valves and other issues like the ones outlined above, properly maintain your appliances as described in their owner’s manuals.
Additionally, schedule professional appliance maintenance yearly to have a technician thoroughly clean and check all of your home appliances. The tech will test the operation of the solenoid valves as well as all of the other controls and components in your appliances.
With Sears Home Services, you can schedule professional cleaning and maintenance service for all of your home appliances in one visit to keep them all in top shape and lasting longer.
During maintenance service, our technicians can spot and resolve problems with solenoid valves or other components that could result in unexpected failures during the year.
At Sears Home Services, we have experienced techs who are experts at diagnosing and fixing all types of solenoid valve problems as well as all other appliance failures.
Schedule your laundry appliance repair now!
Trust our experienced technicians to handle your washer and dryer repairs, regardless of the problem.
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Glossary Terms
Wattage is the measure of electrical power expressed in watts (W), indicating the rate at which a device consumes energy.
A washer screw is a fastening device that combines a screw and a washer, designed to distribute the load of a screwed fastening more evenly and to prevent the screw from loosening under vibration.
A voltage meter, commonly referred to as a voltmeter, is an instrument used for measuring the electrical potential difference, or voltage, between two points in an electrical or electronic circuit.
A multimeter is an electronic measuring instrument that combines several measurement functions in one unit, commonly used to measure voltage, current, and resistance.
Common Appliance Symptoms
The most common reasons your Whirlpool washer won't stop filling are a clogged water valve, a bad water-level pressure switch, or a malfunctioning electronic control board.
The most common reasons your Whirlpool washer won't spin or drain are a seized gearcase, a broken motor, or a failed door switch.
The most common reasons your Whirlpool washer won't turn off are a malfunctioning electronic control board, broken motor or a jammed door lock assembly.
The most common reasons your Whirlpool washer won't start cycle are a malfunctioning electronic control board, jammed door lock assembly or a faulty user interface.
The most common reasons your Whirlpool washer vibrates are a damaged suspension rod, malfunctioning electronic control board or a dead fan.
The most common reasons your Whirlpool washer is experiencing the rinse cycle not working are a broken lid switch, a bad water-level pressure switch, or a malfunctioning electronic control board.