Dishwasher Hums but No Water: Troubleshooting and Fixes

A humming dishwasher that doesn’t fill with water can be frustrating, especially when you’re left with dirty dishes piling up. This issue is surprisingly common and often signals a minor problem that can be resolved without professional help. 

The hum typically indicates that the dishwasher’s motor or components are working, but water isn’t reaching the appliance. This guide lists down the potential causes of a dishwasher that hums but doesn’t fill with water and provides step-by-step instructions to troubleshoot and fix the issue.

Why is My Dishwasher Humming But Not Filling With Water?

Before diving into fixes, it’s essential to understand why this problem occurs. The humming sound suggests that the motor or solenoid is operational, but something is obstructing the water supply. Common reasons include:

Clogged or Faulty Water Inlet Valve

The water inlet valve controls the flow of water into the dishwasher. If it’s clogged with debris or malfunctioning, water won’t enter the appliance, even though the motor is trying to operate.

Water Supply Issues

A closed or kinked water supply line can prevent water from reaching the dishwasher. Alternatively, low water pressure could be the culprit.

Float Assembly Problems

The float assembly regulates water levels inside the dishwasher. If it’s stuck or defective, it may incorrectly signal the machine that it’s full, stopping the water flow.

Blocked or Malfunctioning Solenoid

The solenoid valve opens and closes to allow water into the dishwasher. If it’s jammed or defective, it can cause the dishwasher to hum without filling.

Electrical or Motor Issues

Problems with the dishwasher’s internal wiring or motor can cause the hum without facilitating proper water flow.

How Do You Fix a Dishwasher That Won’t Fill With Water?

Follow these steps to identify and resolve the issue. Each step addresses a specific potential cause, starting with the simplest solutions and progressing to more technical fixes.

1. Ensuring the Water Supply is Functioning

Begin by confirming that water is reaching the dishwasher. Locate the water supply valve, typically found under the sink. Make sure it’s fully open; even a slightly closed valve can restrict water flow. If the valve is open, inspect the water supply hose connected to the dishwasher.

Pull the dishwasher slightly forward to access the back and examine the hose. Look for kinks or bends that may be obstructing water flow. Straighten any kinks carefully to avoid damaging the hose. If the hose appears worn or cracked, it may need replacement.

To verify water pressure, disconnect the hose from the dishwasher and place the loose end in a bucket. Turn on the water supply briefly. A steady, strong flow indicates sufficient pressure, while a weak trickle may suggest an issue with your home’s plumbing system that requires professional attention.

2. Checking the Float Assembly

The float assembly is a small, dome-shaped component located at the bottom of the dishwasher’s tub. Its function is to monitor and control the water level, preventing overfilling. If the float becomes stuck or obstructed, it may send incorrect signals to the dishwasher, stopping the water from filling.

Open the dishwasher door and gently press down on the float. If it resists or doesn’t move freely, inspect the surrounding area for food particles, soap residue, or debris. Use a damp cloth or sponge to clean the area thoroughly.

Once cleaned, test the float again by moving it up and down. It should move without resistance. If the float appears damaged or doesn’t function properly, it may need replacement.

3. Cleaning the Water Inlet Valve

The water inlet valve is responsible for controlling the flow of water into the dishwasher. If it becomes clogged with debris or mineral deposits, it can block the water supply. To access the valve, first unplug the dishwasher and turn off the water supply for safety.

Remove the kick plate at the base of the dishwasher to expose the valve. Disconnect the water supply hose from the valve and inspect the small mesh screen inside for blockages. Use a toothbrush or a small brush to gently clean the screen, ensuring all debris is removed.

If cleaning doesn’t resolve the issue, the valve itself may be defective. Using a multimeter, test the valve for electrical continuity. A failed reading indicates the valve needs replacement.

4. Testing and Adjusting the Solenoid

The solenoid works in conjunction with the water inlet valve, opening to allow water into the dishwasher. If it’s faulty, the dishwasher may hum but not fill. Locate the solenoid near the water inlet valve and inspect it for visible damage or debris.

In some cases, the solenoid may become stuck. Tap it gently with the handle of a screwdriver to loosen it. Then, use a multimeter to check its electrical continuity. If it fails the test, replace the solenoid.

5. Inspecting the Motor for Obstructions

The motor generates the necessary force to circulate water in the dishwasher. A humming sound from the motor could indicate it’s attempting to work but is obstructed. Unplug the dishwasher and remove the lower access panel to inspect the motor.

Look for signs of debris, such as food particles or broken glass, that may be blocking the motor’s movement. Carefully remove any obstructions using tweezers or a small vacuum. Once clear, rotate the motor shaft manually to ensure it moves freely.

If the motor still hums but fails to operate, it may have an internal electrical fault and require professional repair or replacement.

Frequently Asked Questions 

Why is my dishwasher draining but not spraying water?

If your dishwasher’s water spray is weak or absent, the problem might be due to insufficient water supply, a faulty circulation pump, or issues with the spray arms. 

Why does my Bosch dishwasher make a humming sound?

A Bosch dishwasher’s draining process is usually accompanied by a quiet buzzing sound produced by the drain pump. However, if the buzzing noise becomes louder or more pronounced, it could signal a potential issue, such as a clogged drain pump or a damaged impeller. 

Conclusion 

A dishwasher that hums but doesn’t fill with water often signals a fixable issue, such as a blocked water inlet valve or a stuck float assembly. By carefully inspecting and addressing these components using the detailed steps outlined above, most homeowners can resolve the issue without professional assistance.

For more complex electrical problems, such as a faulty motor or solenoid, it’s best to consult a technician. Regular maintenance and cleaning can help ensure your dishwasher operates smoothly, minimizing the risk of similar problems in the future.