How do I clean the drain pump when it is blocked?

Switch off the appliance and unplug it, then open the service flap and remove the drain hose from its retainer to pour out residual water into a suitable container. Carefully unscrew the pump cover, clean the interior, pump cover thread, and pump housing, ensuring the impeller can rotate freely. Refit the pump cover with the handle in a vertical position, then close the service flap. (Page 44-45)