How often should you deep clean your dishwasher?

Grease and limescale clog jets and leave dishes dirty.

A blocked filter recirculates dirty water, so dishes come out gritty and you rewash them by hand, which defeats the point of the appliance. Grease and food trapped in the door seal and the filter also produce the smell people blame on the drain.

1. Remove and wash the filter. Bottom centre, usually a twist to release. Rinse under a hot tap and scrub with a brush. Most people have never removed theirs, and it is the single highest-impact step here.
2. Clear the spray arm jets. Lift the arms off, which usually unclip or unscrew, and poke a cocktail stick or fine wire through any blocked holes. Rinse them through.
3. Wipe the door seal and the door edge. Black mould and grease collect in the folds of the seal and along the bottom lip of the door, which the wash never reaches.
4. Check the drain area. Remove any glass, labels or debris from the sump below the filter.
5. Run a hot cycle with a cleaner. Either a proprietary dishwasher cleaner, or a cup of white vinegar in a bowl on the top rack, on the hottest cycle with the machine otherwise empty.
6. Descale if you are in a hard water area. Citric acid or a descaling product on a hot empty cycle removes the scale on the element that quietly increases running cost.
7. Check the salt and rinse aid. On machines with a softener compartment, keeping the salt topped up prevents scale in the first place.

• Dishes coming out with grit or food residue on them
• A film or white cloudiness on glassware, which indicates hard water or a rinse aid problem
• A stale or eggy smell when you open the door
• Standing water left in the bottom after a cycle, which means the drain or filter is blocked
• Cycles taking longer than they used to

• Never removing the filter, which is by far the most common omission
• Pre-rinsing dishes completely, which sounds helpful but removes the food that modern detergent enzymes need to work against, leading to poorer cleaning
• Using bleach in a stainless steel interior, which damages it
• Overloading so the spray arms cannot rotate freely, which is the actual cause of most poor wash results
• Ignoring the salt reservoir in hard water areas

• Hard water areas need descaling far more often
• Heavy use in a large household means monthly at minimum
• Machines that mostly run short eco cycles need an occasional hot cycle to clear grease, since low temperature cycles do not

Standing water that persists after clearing the filter and checking the drain hose points to a failed pump or a blocked waste connection. Leaks from the door seal or the base need a technician.