When a dishwasher hums, pauses, or starts a cycle but the tub stays dry, the useful question is whether water is being prevented from entering or whether the machine never reached the fill step. In a U.S. kitchen, that means checking the under-sink shutoff, door/cycle state, float area, and visible supply line before ordering an inlet valve. The same symptom can come from a simple interrupted cycle or from a component that needs service, so work from the accessible water path inward.
START HERE
If you need the short version, try these steps first.
- Confirm the dishwasher is not in a delay-start, pause, or canceled state.
- Close and latch the door normally; do not slam it to force the latch.
- Start a cycle and wait through the initial drain or pause described in the manual.
Check these safety points before you start.
- Turn off electrical power before touching any user-accessible component inside the dishwasher tub beyond normal cleaning.
- Do not force a corroded shutoff valve or disconnect a water line that is leaking or difficult to operate; use a plumber or appliance technician.
- Never bypass an overfill float, door switch, or other safety interlock to make a dishwasher fill.
Listen for the difference between no fill and an interrupted cycle
Start a normal cycle with the racks loaded normally and listen from outside the closed machine. Many dishwashers begin with a brief drain or pause before filling, so a few seconds without water is not automatically a fault. If the door was opened, power flickered, or Start/Resume was not completed, the control may be waiting rather than trying to fill.
Whirlpool's current U.S. guidance for a dishwasher that will not fill specifically calls out the water-supply valve and an open or unlatched door as early checks. Use the exact resume procedure in your owner's manual because some models require the door to be closed within a short interval after pressing Start/Resume.
- Confirm the dishwasher is not in a delay-start, pause, or canceled state.
- Close and latch the door normally; do not slam it to force the latch.
- Start a cycle and wait through the initial drain or pause described in the manual.
- If the tub still stays dry, move to the water-supply checks under the sink.
- Stop troubleshooting if a breaker trips, wiring smells hot, or water is leaking near electrical parts.
The under-sink shutoff is the simplest place to lose the water supply
Most built-in U.S. dishwashers are fed by a dedicated hot-water line from a shutoff valve under the kitchen sink. Confirm that valve is fully open and look for a braided or copper supply line that has been crushed, sharply bent, or disturbed by stored items. Do not force an old valve that is seized or already damp around the stem.
Whirlpool's installation support says its dishwasher supply needs adequate pressure and an unrestricted line; current guidance lists roughly 20 to 120 psi for the appliance connection. You do not need to measure pressure as a first homeowner step, but weak flow at multiple hot-water fixtures can be a clue that the issue is broader than the dishwasher.
A restricted float can tell the machine the tub is already full
Some dishwashers use an overfill-protection float in the tub. A utensil, label, food debris, or mispositioned part can keep that float from moving as intended. With power off to the dishwasher, remove obvious loose debris around the float and check only the movement the owner's manual identifies as user-accessible.
Do not defeat, tape down, or bypass an overfill device to make the machine take water. If the float moves freely but the machine still does not fill, the problem may be the switch, inlet valve, control, wiring, or another internal component that requires diagnosis.
Drain-hose routing can create a fill symptom after installation changes
If the problem began after a dishwasher replacement, sink plumbing change, or disposal installation, inspect the drain-hose routing as well as the supply. Whirlpool specifies a high loop for many installations and notes that improper drain routing can allow siphoning behavior that interferes with normal operation.
Do not randomly reroute plumbing based on a generic diagram. Dishwasher, air-gap, disposer, and local-code requirements vary, so compare the installation to the manual for your exact model and the plumbing arrangement under your sink.
Know when the inlet valve is a service diagnosis, not a guess
If the shutoff is open, the door/cycle state is correct, the visible supply line is not kinked, and the float area is clear, an inlet-valve or control problem becomes more plausible. That does not make part replacement the next automatic step. The valve is connected to both household water and appliance electrical circuits.
For a rental, document the symptom and notify the property manager before disconnecting plumbing or pulling the machine from the cabinet. For an owner-occupied home, schedule appliance service if diagnosis requires removing the toe kick, measuring live voltage, or disconnecting the inlet valve.
Before you call it done
- The dishwasher was allowed to pass through its normal initial drain/pause before being judged as not filling.
- The door and Start/Resume state were checked without forcing the latch.
- The under-sink hot-water shutoff is open and the visible supply line is not sharply kinked or leaking.
- The user-accessible float area is free of obvious debris and the safety device was not bypassed.
- Internal valve, wiring, control, or pressure diagnosis is being left to qualified service when basic checks do not solve the problem.