Standing water at the bottom of the tub after a cycle is almost always a blockage — and often one you can clear in fifteen minutes.
An inch of cloudy water left in the bottom of the dishwasher after a finished cycle means the machine could not push it out. The drain path is short: filter, sump, pump, hose, then either the garbage disposal or the sink drain. A blockage anywhere along it produces the same symptom.
Start with the filter
Nearly every dishwasher built in the last fifteen years has a removable cylindrical filter in the floor of the tub. Twist it counter-clockwise, lift it out, and rinse it under hot water with a soft brush. If it is coated in grease and food, you have found at least part of your problem — and this is a part that needs cleaning monthly, not yearly.
Then work along the drain path
- Scoop out the standing water with a cup and sponge so you can see the sump.
- Check the sump area for glass chips, labels, fruit stickers and bones.
- Look at the drain hose under the sink for kinks or a sagging low spot holding water.
- If your dishwasher drains into a garbage disposal, confirm the knockout plug was removed at installation — a surprisingly common cause on new installs.
- Run the disposal for thirty seconds and try a drain-only cycle again.
When it is not a blockage
If everything is clear and the machine still holds water, the drain pump or its control may have failed. You will often hear a faint hum with no water movement. Some brands also have a check valve that sticks, letting water flow back into the tub after the pump stops.
“Clean the filter monthly and you will avoid the majority of dishwasher service calls we attend.”
Odour, cloudy glassware and poor cleaning usually clear up on their own once drainage is restored. If it does not, it is worth having the spray arms and water inlet checked at the same visit.