Dishwasher stops and displays E05, often after filling; spray arms may not rotate and dishes remain dirty.

Safety first: Disconnect power and close the water tap. Allow the machine to cool before working near hot water components.

• Check for obvious blockages: Remove the lower basket, filters, and sump cover. Use a flashlight to inspect the sump for glass, bones, or debris that could jam the circulation pump inlet. Remove any foreign objects with pliers.
• Inspect spray arms: Remove upper and lower spray arms and rinse under running water. Clear blocked jets with a toothpick. Blocked arms can overload the pump.
• Access circulation pump: Lay the dishwasher on its back (protect the floor) and remove the bottom cover. Locate the circulation pump attached to the sump. Check that the wiring connector is secure and not burnt.
• Check impeller movement: If accessible, gently rotate the pump impeller by hand. It should move freely with slight resistance. A seized or very stiff impeller indicates a failed pump.
• Electrical test: With a multimeter, measure the pump motor winding resistance and compare with service data. An open circuit or shorted winding means the pump must be replaced.
• Replace pump if needed: Disconnect hoses and wiring, remove the pump from the sump, and install a compatible Grundig circulation pump. Ensure all seals are correctly seated to prevent leaks.
• Reassemble and test: Refit the base, stand the dishwasher upright, reconnect water and power, and run a test program.