Why Is My Dishwasher Not Filling With Water?

How Dishwasher Filling Works

A normal fill begins when the control sends power to the water inlet valve; water flows through the supply line and 90-degree elbow into the tub until a float or flow sensor tells the control to stop. If the shutoff is closed, pressure is low, the inlet screen is clogged, the float is stuck, or the door switch isn’t made, the tub won’t fill. Major brands list these items among first checks in their owner and service materials.

Electrical supply matters as well. Dishwashers are designed for 120 V, 60 Hz on a dedicated 15–20 A branch circuit; live voltage is present at the inlet valve during fill, so power must be isolated before removing toe-kicks or panels.

Water conditions also play a role. Manufacturers commonly specify incoming pressure in roughly the 20–120 psi range, and hot supply near 49–65 °C to ensure proper detergent action and sensor behavior. If pressure sags or the stop valve isn’t fully open, the machine may hum without filling.

Finally, drain configuration influences filling. If the drain hose lacks a high loop or required air gap, siphoning can empty the tub as fast as it fills. Installation instructions from major brands call for a high loop or an air gap to code.

Fast, Safe Checks You Can Do Now

Cut power at the breaker before opening panels. However, the checks below are non-invasive and can be done with the door closed.

1. Open the under-sink shutoff fully and start a cycle. A hard hum with no water often points to a closed valve or clogged inlet screen.
2. Inspect the supply hose for kinks and confirm the 90-degree elbow at the valve isn’t stressed.
3. Lift and drop the float gently; it should move freely and click the switch. Stuck up equals no fill.
4. Close the door firmly. If the latch isn’t made, the control won’t energize the valve. Some models won’t even start a cycle until the door is latched within a few seconds.
5. Check for fault codes. On Bosch, E15 indicates water in the base pan, which locks out filling; E16 or E17 indicate an inflow or filling fault.
6. Run the hot tap at the kitchen sink for 30–60 seconds before starting the dishwasher. Incoming water should be around 49–65 °C for normal cycles.
7. In cold snaps, feel the supply line under the sink. Lines on exterior walls can freeze, starving the dishwasher until thawed. Local city guidance explains prevention and safe thawing.

If none of these restore a fill, further diagnosis requires tools and electrical testing.

Deeper Causes, Fixes, And Safety Boundaries

Inlet Valve Clogged Or Defective

Sediment collects on the valve’s inlet screen, or the solenoid fails electrically (open circuit) so the valve won’t actuate. We shut off water, isolate power, remove the line, inspect the screen, and test coil resistance. If the coil is open or the valve leaks, we replace it and check for drips on reassembly. Manufacturer repair and service literature place the inlet valve among the top no-fill causes.

Float Switch Or Flow/Pressure Sensor Fault

A stuck float or failed microswitch tells the control the tub is already full, while some models use flow meters to confirm inflow. We free the float, verify continuity, and confirm sensor feedback in diagnostics where supported. Bosch error guidance links E16/E17 to inflow faults.

Door Latch Or Control Not Making

A misaligned strike or failed latch switch blocks power to the valve. We realign, test continuity and, where applicable, update software. Whirlpool documentation highlights door-closure and control checks as first-line steps.

Drain Siphoning Or Incorrect Install

Without a proper high loop or air gap, wastewater can siphon back during fill. We correct the routing and, where required by local by-laws, install an air gap. GE and Whirlpool installation instructions lay out loop height and air-gap options; local cross-connection control follows CSA B64.10.

Low Pressure Or Frozen Lines

Municipal work, clogged aerators, or freezing inside sink cabinets can drop flow below spec. Consequently, the dishwasher times out on fill. City guidance explains how to prevent and thaw frozen pipes safely.

Stop Immediately If You Notice:

• Water in the base pan or active leaks under the sink.
• Tripped breakers, burning smells, or heat at the junction box.
• Recurrent Bosch E15 or visible drip from the valve or elbow.
  For any mains-power work, hire a Licensed Electrical Contractor; the Electrical Safety Authority provides a lookup to verify licensing.

What Our Technician Does On A No-Fill Call:

1. Kill power, remove the toe-kick, and check for base-pan water or leak-tray events. If wet, we resolve the leak before restoring fill.
2. Confirm correct electrical supply and that the door switch closes; then verify the control outputs power to the inlet valve during the fill step.
3. Measure line pressure, clean the inlet screen, and replace the valve if the solenoid is open or the valve drips.
4. Inspect drain routing; add a high loop or air gap per the install guide and local code; then run a wet test and recheck for leaks.

As for electrical safety, any work beyond unplugging or breaker-off user checks should go to a Licensed Electrical Contractor. The Electrical Safety Authority explains the rules and offers a public directory to verify credentials, which protects both your warranty and your insurance. 

FAQ

Why does it hum but stay dry?

Typically the valve coil energizes but flow is blocked by a closed stop, kinked hose, or a clogged inlet screen. Clearing the screen and opening the stop often restores filling.

What fill-related codes do Bosch dishwashers show?

E16 and E17 point to water inflow or filling faults; E15 indicates water in the leak tray, which intentionally stops filling for safety.

What water temperature should I aim for at the sink?

Manufacturers commonly recommend hot water of at least about 49 °C, with many models optimized around 49–65 °C. Running the tap first delivers hot water to the inlet right away.

Sources

1. Bosch Owner Support (E15, E16/E17);
2. GE Appliances (electrical requirements; water temperature guidance);
3. Whirlpool Product Help and service documentation (door, start, and diagnostic checks; installation with air gap/high loop);
4. Samsung Support (water pressure 20–120 psi);
5. Electrical Safety Authority (finding a Licensed Electrical Contractor);
6. CSA Group (B64.10 backflow).