Dishwasher displays H03 and will not proceed, water remains in tub

Safety first: Turn off power at the breaker and avoid reaching into water with power connected.

• Clean filters: Open the door, remove the lower rack, twist out the Panasonic fine filter and coarse filter, and rinse thoroughly under running water. Remove any food debris from the sump area.
• Check drain hose: Inspect the drain hose at the back and under the sink. Ensure it is not kinked, crushed, or installed too high. Disconnect from the sink trap and blow through it or flush with water to clear blockages.
• Inspect air gap (if fitted): If your installation uses a countertop air gap, remove the cap and clean out any debris.
• Check drain pump for blockage: Lay towels, tilt the dishwasher slightly back, remove the lower front kick panel, and access the drain pump at the sump. Remove the pump cover and check for glass, bones, or labels jamming the impeller. Rotate the impeller gently to ensure it spins freely.
• Test pump operation: After reassembly, run a cancel/drain function. If the pump hums but does not move water, or is silent, the pump motor may be defective and should be replaced.

Persistent H03 after clearing blockages usually indicates a failing drain pump or wiring issue that may require professional service.