Safety first: Unplug and remove all tanks and filters before cleaning.

Deep clean tanks: Empty both clean and dirty water tanks. Wash with warm water and a small amount of mild detergent. Rinse thoroughly and allow to dry completely.
Sanitise hoses: Fill the clean tank with a solution of warm water and a small amount of white vinegar (check manual for compatibility). Run the machine briefly to circulate, then flush with plain water.
Dry filters: Remove filters and wash if applicable. Allow to dry for at least 24 hours before refitting.
Store dry: After use, leave tanks and filter covers slightly open so moisture can evaporate.

Strong musty or sour smell from the machine during use

Possible Causes