First, distinguish two things that look alike. A small amount of water sitting in the recessed sump is normal on many dishwashers and keeps seals from drying out. Water lying across the flat floor of the tub, enough to slosh when you open the door, means the last cycle did not drain.
Before You Reach Into the Tub
Switch the dishwasher off at the breaker, or unplug it if the plug is accessible under the sink. The water in there is dirty rather than dangerous, but the heating element may still be hot and you are about to put your hands near it and near sharp debris. Let it cool, then bail the standing water out with a cup and finish with towels so you can see what you are doing.
Checks That Solve Most of These
- The filter. Most current Whirlpool dishwashers have a removable filter assembly in the floor of the tub that the owner is expected to clean. Twist and lift it out as the manual describes, rinse it under a tap with a soft brush, and clear anything caught in the housing below it. This one item accounts for a large share of drainage calls.
- The sump area. With the filter out, look for glass fragments, fruit stickers, olive pits or a fallen bottle cap sitting over the drain opening.
- The drain hose under the sink. Look for a sharp kink where the dishwasher was pushed back into place.
- The air gap, if your sink has that small chrome cylinder on the deck. Lift the cover and clear any debris inside it.
- The garbage disposer. If the dishwasher drains into a disposer that was newly installed, the knockout plug inside the disposer inlet may never have been removed. Run the disposer for a few seconds before retesting.
What Needs a Technician
If the filter is clean, the hose is clear and the disposer is not the culprit, what remains is the drain pump, the check valve or the control that commands them, and those sit under the tub. A pump that hums without moving water, a machine that trips a breaker, or water appearing on the floor rather than in the tub all warrant stopping and calling. Book a Whirlpool dishwasher repair visit and mention whether the pump makes any sound at all during the drain phase.