Hobart dishwasher stops mid-cycle and displays E4; machine may have standing water in the tank or sump.

Safety first: Disconnect power and ensure water is cool before accessing the sump or drain components.

• Inspect drain hose: Check that the drain hose from the dishwasher to the building drain is not kinked, crushed, or routed above the recommended height. Clear any visible obstructions at the end of the hose.
• Clean air gap and external trap: If your installation uses an air gap or standpipe, remove and clean debris, food particles, or scale that may be blocking flow.
• Check drain pump area: Remove the lower wash arm and filters to access the sump. Look for broken glass, food debris, or labels obstructing the drain intake. Carefully remove obstructions with gloves.
• Test drain function: Restore power and run a drain or cancel cycle. Listen for the drain pump. If it hums but does not move water, the impeller may be jammed or the pump failed.
• Service or replace pump/valve: If the pump is silent or trips breakers, or if the drain solenoid does not actuate, the drain pump or drain valve assembly likely needs replacement by a qualified technician.