Dishwasher Not Draining? Five Fixes to Try Before You Replace It
Standing water in the bottom of a dishwasher is one of the most common reasons people start shopping for a new one. In most cases, the cause is a blockage you can clear yourself in under an hour.
Check these first
- Was the cycle interrupted? A cycle cancelled mid-way, or a power blip, leaves water in the tub. Run a short rinse or drain cycle.
- Is the sink draining? The dishwasher drains into the same pipework as the kitchen sink. If the sink is slow, the problem is the household drain.
- Is the garbage disposal clear? Run the disposal for a few seconds; a full disposal blocks the dishwasher drain.
Five common causes
1. Clogged filter
Most modern dishwashers have a removable filter in the base of the tub. Twist it out, rinse it under hot water and scrub the fine mesh with a soft brush. Bosch, KitchenAid, Whirlpool and many others recommend cleaning it regularly.
2. New garbage disposal knockout plug
If the problem started right after a new garbage disposal was installed, the knockout plug inside the disposal’s dishwasher inlet may never have been removed. It has to be punched out before the dishwasher can drain.
3. Kinked or blocked drain hose
Check the hose under the sink for kinks, and make sure it has a high loop or an air gap so dirty water cannot flow back into the dishwasher.
4. Blocked air gap
If your sink has a small chrome cap next to the faucet, that is the air gap. Pull off the cover and clean out debris.
5. Failed drain pump
If you hear humming but no water moves, something may be jammed in the pump — often broken glass or a fruit pit. With the power off, remove the filter and look into the sump. If the pump is clear but still does not run, it may need replacement.
What not to do
- Do not pour chemical drain cleaner into a dishwasher; it can damage seals and pump parts.
- Do not keep running cycles with standing water — it overloads the pump.
Repair or replace?
A drain pump replacement is a moderate repair, and on a dishwasher under about six years old it is usually worth doing. On an older, inexpensive machine with other problems, replacement may make more sense — see our repair-or-replace guide. For a technician’s walkthrough of the same problem, see this guide to a dishwasher not draining water. And if it is time to replace, our dishwasher removal guide covers the old one.