How Do Solenoids Work?
Solenoids are indispensable components in many home appliances, enabling precise control of water and gas flow by opening and closing valves.
But what exactly is a solenoid, and how does it work? In this article, we’ll dive into the mechanics of solenoids, their role in different appliances, and how to diagnose and repair solenoid failures.
By understanding how solenoids work and knowing how to diagnose and repair common issues, you can ensure your appliances run smoothly and efficiently.
KEY TAKEAWAYS
- Solenoids are electromechanical devices that convert electrical energy into mechanical motion. They consist of a coil, a movable plunger, and a spring mechanism. When electricity flows through the coil, it creates a magnetic field that moves the plunger, allowing precise control over operations like opening and closing valves in appliances.
- Solenoids manage water inlet valves in washers and dishwashers, control water dispensers and ice makers in refrigerators, and ensure safe gas flow in gas dryers.
- Common issues such as dishwashers not filling, refrigerators not getting water, or gas dryers failing to heat can be attributed to solenoid malfunctions. Proper diagnosis and troubleshooting is needed to determine whether a failed solenoid is causing the failure.
What is a Solenoid?
A solenoid is an electromechanical device that converts electrical energy into mechanical movement. At its core, a solenoid consists of a coil of wire, a movable plunger (also called an armature), and a spring mechanism. When electricity flows through the coil, it creates a magnetic field that moves the plunger, triggering a mechanical action such as opening or closing a valve.
How Solenoids Control Water Valves
In appliances like washers, dishwashers, and refrigerators, solenoids are used to regulate the flow of water. Here’s how they work:
Washer and Dishwasher Water Valves
Solenoids in washers and dishwashers are connected to water inlet valves. When the appliance receives a signal from its control board, it sends an electrical current to the solenoid.
The energized solenoid generates a magnetic field, pulling the plunger inside the valve open, allowing water to flow into the appliance.
When the signal stops, the solenoid de-energizes, and the spring mechanism pushes the plunger back, shutting off the water flow.
Refrigerator Water Valves
In refrigerators with a water dispenser and ice maker, solenoids control the flow of water to specific components. For example, when you press the water dispenser lever, the control system activates the main water supply solenoid and the water dispenser solenoid, allowing water to flow through the dispenser.
How Solenoids Control Gas Valves in Gas Dryers
Gas dryers rely on solenoids to regulate the flow of gas to the burner assembly. Here’s how they function:
The control board or timer sends electrical current to the gas valve solenoids, which are located on the burner assembly. The solenoids are connected in a safety circuit with a flame sensor to prevent the gas valve assembly from opening to allow gas flow if the flame sensor doesn’t detect a flame or an igniter that’s hot enough to light the burner when gas flows through the burner.
When safe conditions are met in the safety gas valve circuit, the solenoid gas valve assembly opens all of the solenoid valves to allow gas to flow through the burner to ignite and heat the dryer.
Once the desired temperature is reached, the control board deactivates the solenoid, cutting off the gas supply.
This process is crucial for safe and efficient operation, ensuring that gas flows only when it is needed and stopping it immediately when heating is not required.
Diagnosing Possible Solenoid Failures
A malfunctioning solenoid can disrupt the operation of your appliance, whether it's a washer that won’t fill, a refrigerator not making ice, or a gas dryer that won’t heat.
Here’s expert advice on how to identify and diagnose common problems in appliances that may be caused by solenoid failures.
Dishwasher Not Filling
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 filling failure for you.
Washer Won’t Fill
Washers use at least 2 solenoid water valves (hot & cold) to fill the washer tub.
The electronic control or timer provides power to open the valves and fill the washer tub.
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 when the tub is full.
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.
Refrigerator Not Getting Water
Some refrigerators have complex water systems that aren’t easy to diagnose and repair. You’ll typically need to have a service technician diagnose a water supply issues unless you have a basic model with just an ice maker that isn’t getting water.
Here are some troubleshooting tips for a basic fridge with just an ice maker that isn’t getting water.
Water not reaching the ice cube tray could indicate a problem with the water inlet valve, but not always. Here are other reasons that can prevent the ice maker from getting water:
- The refrigerator may not be getting water through your home’s water supply line.
- The water fill tube above the maker can freeze, not letting water into the ice maker.
- A clogged water filter could also cause low or no water flow to the ice maker or the water dispenser.
Start by checking for a frozen fill tube or a clogged water filter.
Next, check the water supply going to your fridge by following these steps:
- Disconnect the water supply line from the water valve.
- Place a bucket under the end of the water supply line.
- Turn on the water to the supply line and check the flow.
If water doesn’t flow from the end of the hose, have a plumber repair the water supply going to your refrigerator.
If water flow through the water line is good, you’ve ruled out a water supply problem as the cause of the failure.
Because you’ve eliminated all of the possible causes of failure, replacing the solenoid water valve will likely fix the water supply problem in your refrigerator.
Because the solenoid water valve in a refrigerator is a relatively low-priced part, you can try to fix the problem on your own by replacing the water valve. Here’s a video that shows how to replace the water valve in a refrigerator:
Gas Dryer Not Heating
Here’s a popular DIY troubleshooting video with technical details of 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.
Proactive Appliance Maintenance Tips
- Replace the water filter in your refrigerator every 6 months to maintain proper water flow.
- Inspect water supply hoses and connections. Ensure hoses are free of kinks and connections are secure to prevent leaks and problems.
- Follow the directions in your appliances’ user manuals to properly clean and maintain them.
- Schedule annual professional appliance maintenance to have a service technician check the water system and all components in your appliances.
With a little proactive maintenance, you can extend the lifespan of your appliances and keep your home running like clockwork.
Schedule your kitchen appliance repair now!
From refrigerators to dishwashers, our experienced technicians are equipped to repair all your kitchen appliances, providing fast and reliable service.
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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.
Natural gas is a fossil fuel used primarily for heating, cooking, and electricity generation. It's a hydrocarbon gas mixture consisting mainly of methane, but it also contains smaller amounts of other hydrocarbons and sometimes sulfur compounds.
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.
Common Appliance Symptoms
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