Before you start
A little water in the bottom of the dishwasher, around the filter area, is normal on many models. A layer that covers the tub floor is not. Turn off the dishwasher’s power at the breaker or unplug it before you reach into the bottom, and scoop the water out with a cup and towels.
1. Clean the filter
Most dishwashers made in the last decade or so have a manual filter, usually a cylinder in the floor of the tub that twists out, with a flat mesh screen around it. It catches food so the pump doesn’t have to deal with it, and when it clogs, water can’t reach the drain. Twist it out, rinse it under the tap with a soft brush, clear anything in the sump underneath, and lock it back in place. Many manufacturers suggest cleaning it every few weeks.
2. Run the garbage disposal
If your dishwasher drains through a garbage disposal, food sitting in the disposal can block it. Run the disposal with cold water for a few seconds, then try a drain cycle.
3. A new disposal? Check the knockout plug
New garbage disposals ship with a plastic plug in the inlet where the dishwasher hose connects. It has to be knocked out during installation. If your dishwasher stopped draining right after a new disposal went in, a plug that was never removed is the most likely cause.
4. Check the drain hose and air gap
Look under the sink for a kinked or crushed drain hose. The hose should rise in a high loop, or connect to an air gap, before it drops to the drain, so dirty sink water can’t flow back into the dishwasher. If you have an air gap, the small chrome cap on the sink deck, pull the cap off and clear any food packed inside.
5. Check the sink drain
If the kitchen sink itself drains slowly, the dishwasher can’t drain into it either. That’s a plumbing clog, not a dishwasher problem.
6. Look for a broken glass or a seed in the sump
Glass shards, bones, fruit pits and labels from jars can get past the filter and jam the drain pump or its check valve. With the power off and the filter removed, check the sump opening carefully, wearing gloves.
When it’s the drain pump
If the filter, disposal, hose, air gap and sink are all clear, the drain pump or its check valve is the next suspect. A humming sound near the end of the cycle with no water moving usually means the pump is jammed or failing. Silence can mean a failed pump, a wiring problem or a control issue. Drain pumps are a common, reasonable repair on most dishwashers.
A note on hard water
North County’s hard water doesn’t usually stop a dishwasher from draining, but it does build scale on the filter and in the spray arms over time. A rinse aid and a regular cleaning cycle help keep both clear.
Don’t pour chemical drain cleaner into a dishwasher. It can damage the pump and seals, and it makes the water dangerous for whoever works on it next.
If you’re in North County San Diego and the dishwasher still won’t drain, you can book a dishwasher repair with “Won’t drain” already filled in. The diagnostic visit is $89 for homes and $129 for commercial properties.
