Won't fill with water
A dishwasher that won't fill is failing somewhere in a short chain: house hot water supply → inlet valve → internal hose → tub, with a float switch that tells the control 'stop filling.' The chain is shorter than a washer's because dishwashers only take hot water (single valve, not dual) and fill to a much lower level. Failures cluster at two points. First is the float switch — a small plastic dome inside the tub that rises with water. If the float is stuck up (debris underneath or a broken pivot), the control already thinks water is present and refuses to open the inlet valve. Second is the inlet valve itself, whose small mesh screen clogs with mineral sediment and rust particles over years. Before assuming the inlet valve has failed electrically, lift and release the float switch a few times, then check for flow restriction at the screen. These two checks resolve the majority of fill failures.
Safety
Critical- Kill the breaker before inlet valve work: Inlet valves connect to the dishwasher's electrical circuit at 120V. Turn off the dishwasher's dedicated breaker before removing the kick plate or disconnecting supply lines. Confirm power is off with a non-contact voltage tester before reaching into the cavity.
- Close the supply valve before disconnecting lines: The supply line to the dishwasher is under constant pressure. Always close the supply valve under the sink before disconnecting the line at the inlet valve, or water will spray out and can reach the control board and cabinet wiring. Have a towel ready for residual water inside the line itself.
- Old saddle valves often fail during testing: Dishwashers connected via a saddle valve (a small piercing valve on a supply pipe, common in older installations) sometimes fail to close fully or crack when operated. If you have a saddle valve, be prepared for it to leak after you turn it off and on. Consider replacing with a proper shut-off valve during the repair.
How to approach this
Start by opening the dishwasher and locating the float switch — a plastic dome in the front corner of the tub floor, usually on the right side. Lift the float up and drop it several times; it should move freely and return to rest with a clear click. A stuck or stiff float is the single most common cause of no-fill. Clean the area beneath the float with a damp cloth — food debris and scale can jam the pivot. Next, turn off the dishwasher's breaker and close the water supply valve under the sink. Disconnect the supply line at the inlet valve (behind the lower kick plate) and place the line in a bucket, then briefly open the supply valve to confirm strong water flow — weak or no flow indicates a supply-side restriction. With flow confirmed, inspect the tiny mesh screen inside the inlet valve port for mineral buildup; clean with vinegar or replace if severely clogged. Finally, test the inlet valve solenoid with a multimeter across its terminals — a reading outside 500-1500 ohms typically indicates a failed coil.
Common causes
Ordered by how frequently each component is involved, based on OEM manual analysis.
Stuck float switch
Most commonA small plastic dome in the front corner of the tub rises with water level and tells the control when the tub is full. Debris, mineral scale, or a broken pivot can stick the float in the up position. The control reads 'water present' before water has entered and refuses to open the inlet valve. The symptom is a cycle that starts, makes no fill sounds, and either times out or skips to drain. Lifting and releasing the float manually usually frees it.
Clogged inlet valve screen
CommonThe inlet valve includes a small mesh screen that catches mineral sediment and rust particles from the supply line. Flow rates on dishwashers are much lower than washers, so even mild buildup restricts fill significantly. Clean the screen by disconnecting the supply line and gently pulling the screen out with needle-nose pliers — rinse under running water, soak in vinegar for stubborn scale, and reinstall. Cleaning the screen often restores full fill speed at no parts cost.
Failed inlet valve solenoid
CommonDishwasher inlet valves are single-solenoid devices (unlike dual hot/cold washer valves). The solenoid fails mechanically (sticks closed) or electrically (burnt-out coil). A failed solenoid means no water enters the tub when the cycle starts — complete silence during what should be a fill phase. Testing requires checking resistance across the solenoid terminals — outside 500-1500 ohms typically indicates failure. Replacement valves run $30-60.
Closed or partially closed supply valve
CommonThe hot water supply valve under the sink must be fully open for the dishwasher to fill properly. The valve can be partially closed from adjacent plumbing work, gradually closed by someone nervous about leaks, or — in older installations — be a saddle valve that's partially failed. Fully open the valve, test fill, and consider replacing a saddle valve with a proper quarter-turn shutoff during the repair.
Failed float switch electrical contacts
Less commonThe float's electrical switch — underneath the plastic dome — can fail even when the float moves freely. Worn contacts, corrosion from water exposure, or a broken switch arm can leave the switch reading 'tub full' regardless of actual water level. Diagnose by lifting the float manually while testing continuity across the switch terminals. No change in continuity with float movement indicates switch failure. Replacement switches are typically $15-30.
Parts commonly needed
No verified parts are currently associated with this symptom for the DDW24T998US.
View all parts for this modelStill narrowing things down?
Seeing an error code on your display? Look up your error code → for more specific diagnostic information.
How we verify parts for your model. Parts shown are confirmed at multiple retailers specifically for the DDW24T998US. Cross-referenced against OEM documentation.
About this content. Common causes and FAQs are generated from OEM manual analysis and verified parts data. This is general guidance - your specific model may have different components or access points. Always verify with your model's documentation before ordering parts.