Whirlpool Dishwasher Not Draining: Standing Water Explained

You open the door after a cycle and find a gray pool at the bottom of the tub, with food bits floating in it. Maybe the dishwasher stopped partway and the display shows a code. In a San Francisco kitchen, where the dishwasher often shares a sink drain with a garbage disposer and the cabinet space is tight, there is a short list of reasons the water cannot leave. Most of them are visible from the front.

How the water leaves the machine

A drain pump pushes wash water out of the sump, through a check valve and up a hose. That hose rises into a high loop under the counter, or goes to an air gap on the sink deck, and then connects to the disposer inlet or to the sink drain line. Anything that interrupts that path, from the filter at the bottom to the final connection at the trap, leaves water in the tub.

Likely causes, from easiest to hardest

• Clogged filter or sump. Food, labels, glass shards and seeds collect under the lower rack. This is the cause behind many cases.
• Disposer knockout plug. When a new disposer is installed, a small plug in the dishwasher inlet has to be knocked out. If it was left in, water cannot enter the disposer.
• Disposer or sink clogged. If the sink above drains slowly, the dishwasher cannot empty either, and gray water may even back into the tub.
• Kinked or crushed drain hose. A hose pushed behind the machine during installation or cleaning may be folded.
• Air gap blocked. If your sink has an air gap cylinder, debris inside it stops the flow.
• Drain pump or motor. A pump that is jammed by glass or has failed hums without moving water, or stays silent.
• Check valve problem. If the valve stuck or the flap does not open, flow is restricted.
• Control or sensor. A control that does not start the drain, or misreads the water level, can leave water in the tub.

Checks to try in order

1. Run the disposer. With the sink empty, run the disposer and the faucet briefly to clear its chamber. Then check whether the sink drains freely.
2. Remove standing water. Scoop it out with a cup and a towel. This lets you see the filter and the sump floor.
3. Clean the filter. Take out the lower rack, then follow the instruction sheet to lift out and rinse the filter assembly. Look into the sump for glass or a small object.
4. Look at the hose. Slide the dishwasher forward only if it is not fastened and does not stretch the lines. Look for a bend or kink and straighten it carefully.
5. Check the air gap. If your sink has a small cylinder next to the faucet, lift the cap and clean what is inside.
6. Cancel and restart. Use the cancel or drain option on the dishwasher, close the door and see whether the pump starts.
7. Write down the code. A display message gives the technician a lead. For example, F9E1 is listed as a long drain, meaning the dishwasher is not draining, and F9E2 is listed with a potential cause of a drain motor error.

Why a hose loop and an air gap matter

Building codes and installation habits differ, but the idea is the same: wastewater from the sink must not siphon back into the dishwasher. A raised loop in the drain hose or an air gap provides that protection. When an installer skipped the loop or flattened it under a cabinet, dirty water can drift back into the tub after every cycle. If you see a smell along with standing water, the connection to the disposer is a good place to ask about.

What not to do

• Do not pour drain cleaner into the dishwasher or the sink. The chemicals can damage seals and are hazardous if they splash.
• Do not reach into the sump with your hand without checking for glass.
• Do not remove lower panels or touch the pump wiring.
• Do not run repeated cycles with water standing in the tub; it spreads the mess and can overflow.
• If the dishwasher shows a protection code and tells you to turn off the water supply, close the water valve and unplug it or switch off its breaker.

When a technician needs to step in

Request a visit when the filter and sump are clean, the sink drains freely, the hose is straight and the water still does not leave. A technician tests the drain pump and its motor, looks at the check valve, and checks the control signal. They also inspect the connection at the disposer and under the sink, which can be hard to see from the front.

Have the model number ready; on a dishwasher it is usually on the door edge or inside the tub rim. Tell us what the display showed and what you cleaned. We diagnose before repairing, provide a written estimate and repair nothing without your approval. See Whirlpool dishwasher repair and the Whirlpool dishwashers guide. The Whirlpool WDT970SAKZ page lists what is on record for that dishwasher.

Frequently asked questions