How to clean a dishwasher

Step by step

1. Pull out the bottom rack to reach the filter in the floor of the tub, under the lower spray arm.
2. Twist the filter and lift it out. Most come apart into a cylinder and a flat mesh. If yours won’t budge, the manual shows how it’s held in.
3. Rinse the parts under the faucet and scrub the mesh with a soft brush and a drop of dish soap. No wire brushes or scouring pads; they can damage the mesh.
4. While the filter is out, lift off the lower spray arm, rinse it, and poke any clogged holes clear with a toothpick.
5. Wipe the door seal and the bottom edge of the door, where gunk collects out of sight.
6. Put the filter back until it locks, then the spray arm, then slide the rack in.
7. Once a month, run the empty machine on its hottest cycle with a dishwasher cleaner in it.

Does your filter come out?

Look under the lower spray arm. A plastic cylinder you can twist is a manual filter, and it needs cleaning by hand. A fixed plastic grid or a ring of holes is a self-cleaning filter: it grinds food up and sends it down the drain, so there’s nothing to take out.

Newer dishwashers usually have the manual kind, because it runs quieter; self-cleaning filters are more common in machines over ten years old. If yours does and nobody has ever opened it, the first clean is the worst one. After that it’s quick.

If it still smells after the filter

Food caught in the filter is the usual cause, so clean that first. If the smell stays, look in this order:

• The door seal and the bottom of the door. A musty smell often starts here.
• Water standing in the bottom after a cycle. The drain is clogged, often at the filter or the drain hose.
• The drain hose under the sink. A kink stops it draining. If it has a loop up high or an air gap on the sink, check that it’s clear.
• The garbage disposal, if the dishwasher drains into it. Run the disposal before you start the dishwasher, so the water has somewhere to go.

A rotten-egg smell that survives all of this can come from the drain line itself. That’s a job for a plumber, not another cleaning cycle.

Cloudy glasses: film or etching?

Rub a cloudy glass with a little white vinegar. If the haze comes off, it’s a film of minerals from hard water, too much detergent or a crowded load; rinse aid and a monthly cleaner help. If it stays, it’s probably etching: the surface of the glass itself is worn, usually from very soft water, too much detergent or long hot cycles. Etching doesn’t come off. Use less detergent and turn the rinse aid down, so the next glasses stay clear.

Vinegar, baking soda or a cleaner?

The filter matters more than anything you pour in. After that, a dishwasher cleaner made for the job, usually with citric acid, is the safe monthly choice.

Vinegar works for a deep clean now and then. Whirlpool’s way: 2 cups (500 ml) of white vinegar in a dishwasher-safe cup on the bottom rack, a full cycle, no detergent. Whirlpool also says vinegar is an acid and using it too often could damage the dishwasher, so keep it occasional.

Skip the baking soda and vinegar combination. An acid and a base cancel each other out when they meet, so you mostly get fizz.

How often

Advice runs from every 2 weeks to every 3 months, depending on who you ask. We say every month, and sooner if you run the machine every day. The sign it’s overdue is bits of food on clean dishes.

Skip these mistakes

• Waiting until dishes come out gritty before checking the filter.
• Forgetting the spray arm holes, which clog with seeds and bits.
• Rinsing every plate before it goes in. It wastes water, and it can fool the machine into running a lighter wash. Scrape, don’t rinse.
• Running vinegar through every week.

Sources

• Consumer Reports, How to Clean Your Dishwasher Filter
• Consumer Reports, How to Clean a Dishwasher
• Whirlpool, Cleaning the Dishwasher Interior
• Whirlpool, Etching or Cloudy Glassware
• Bosch, How to clean your dishwasher
• iFixit, Dishwasher Smells Bad
• Time, steps and frequency: the CozyHaus guides Clean the dishwasher filter and Load the dishwasher.

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