Jackson dishwasher displays E4 and will not drain; standing water remains in the tank or sump after cycle.

Safety first: Disconnect electrical power. Hot water and sharp debris may be present in the sump—wear cut-resistant gloves.

• Clean tank strainer and scrap basket: Remove the Jackson tank strainer, scrap basket, and any pre-filter screens. Rinse thoroughly to remove food solids, labels, and plastic pieces that can block flow.
• Inspect drain outlet and hose: Locate the machine’s drain outlet. Remove the drain hose and check for grease, scale, or foreign objects. Flush the hose with hot water. Verify that any external air gap or floor drain is not blocked.
• Check drain pump impeller: Access the drain pump (often mounted low on the frame). Remove the pump cover and inspect the impeller for broken blades, glass, or bone fragments. Clear obstructions and ensure the impeller spins freely.
• Test drain pump motor: With power off, check the pump motor windings for continuity. If open or shorted, replace the drain pump assembly. With power on (qualified personnel only), verify that the control sends power to the pump during drain.
• Verify drain solenoid (if equipped): Some Jackson models use a drain valve with a solenoid. Ensure the solenoid actuates and the valve opens fully during drain. Replace if seized or burned out.

Do not operate the dishwasher with a partially blocked drain, as this can cause overflows and damage to heaters and seals.