Dishwasher Humming with No Water Entry? Practical Fixes You Can Do Today
Does your dishwasher start humming when you turn it on, but no water ever enters the tub? This frustrating issue is common, with several possible causes. The good news is that with a few practical troubleshooting steps, you can likely get your dishwasher filling properly again.
From inspecting the water supply to testing components like the inlet valve and float switch, we'll cover all the bases. With a bit of perseverance, you can get clean dishes again without the hassle and expense of a service call.
Shut Off Power and Water to Start
Before tinkering with any appliance, it's important to take safety precautions. Start by unplugging the dishwasher or turning off the circuit breaker it runs on. This prevents electric shock while you're investigating the issue.
Next, locate the water supply valve, typically under the sink, and turn it completely off. This will allow you to disconnect and work on the water line freely without any messy leaks.
Inspect the Water Supply Line
With the power and water off, check the supply line that runs from the shutoff valve to the dishwasher's inlet port. This could be the culprit if it's clogged with sediment or has a kink reducing flow.
Disconnect the line from the dishwasher inlet and hold it over a bucket. Turn the shutoff valve back on briefly to flush out any debris. If the flow seems weak, the supply line needs a deeper clean.
To thoroughly remove deposits, disconnect the line at the valve too. Use vinegar or lime remover to break up mineral buildup. For stubborn clogs, insert a tiny brush into the supply line to scrub out any gunk.
Once the line is clear, reconnect it firmly at both ends. Turn the supply back on and check for leaks before moving on.
Clean the Inlet Valve
If water flows freely through the supply line but still won't enter the dishwasher, the inlet valve is the next item to check.
The inlet valve is located inside the dishwasher cabinet, mounted to the bottom with a hose leading in from the supply line. Remove any cover panels to access it.
Examine the valve for any debris clogging the mechanism or mineral deposits around the fittings. Calcium and limescale can prevent the valve from opening properly.
Use an old toothbrush and vinegar solution to scrub deposits away. Soak stubborn buildup for 15 minutes before scrubbing. Operate the valve manually to confirm it's functioning smoothly.
Test the Float Switch
Another part that commonly fails is the float switch. Mounted in the dishwasher tub, this small mechanism detects the water level and shuts the fill valve off when full.
Remove the float switch carefully to inspect it. Look for any cracks in the plastic housing or damage to the contact inside. Test it with a multimeter to check for continuity.
If the float switch seems defective, replacing it with an identical model should have your dishwasher filling again. Make sure to position it properly so it can move up and down.
Inspecting the Door Microswitch
The door microswitch is located inside the door frame of the dishwasher. It is a small plastic device with wire connectors.
To access the microswitch, fully open the dishwasher door. Locate the switch on the right or left side of the door frame.
Carefully disconnect the wires from the microswitch. You may need to loosen a small screw.
Remove the microswitch mounting screws to detach it from the door frame.
Closely inspect the microswitch for any cracked housing or corroded electrical contacts.
Use a multimeter to check for continuity by touching the probes to the electrical terminals. It should show continuity when the switch button is depressed.
If the microswitch shows no continuity or the housing is damaged, replacement is required. Install a new microswitch with the same electrical ratings.
Consider Other Possibilities
In some cases, the cause may be something other than the water supply and valve components:
- A clogged drain pump can prevent proper water circulation.
- Control board issues may prevent cycles from starting.
- A bad motor or bearing problem can stop the wash arms from turning.
If you've tried all the basic troubleshooting steps without success, it's time to call in a repair pro. Major issues with motors, pumps or electronics require specialized expertise.
Know When to Call for Help
While many dishwasher problems are DIY-friendly, don't be afraid to call a technician if you're unsure about electrical repairs or stumped after trying all the typical fixes.
A professional can diagnose tricky issues and has the skills to safely replace complex parts like control boards. Continuing to run a malfunctioning dishwasher can lead to bigger breakdowns.
The good news is repairs commonly cost much less than buying a brand new dishwasher. A bit of troubleshooting before making the call can also minimize service charges.
As you can see, there are several practical things to check when your dishwasher won't fill with water beyond just humming. In most cases, the cause is an obstruction in the supply line, a stuck inlet valve, or a faulty float switch.
With some perseverance and the right diagnostic steps, you can often get the water flowing and avoid a costly appliance repair. Just remember to always disconnect power before tinkering with any dishwasher parts.
Next time your dishes come out dirty and wetness-free, don't panic. Just break out this guide and methodically check each potential culprit. Before you know it, you'll be back to sparkling clean dishes using your perfectly functional dishwasher.