Dishwasher won't drain: diagnose and replace the drain pump
Standing water after a cycle is usually a clog — but when the filter and hose are clear and the pump hums or stays silent, the drain pump has failed.
Applies to: Bosch, Thermador and most European-style dishwashers
Difficulty
Time
30–60 min
Tools
Torx T15 & T20, Flat screwdriver, Towels, Shallow pan or cup
Symptoms
- Standing water in the bottom after a cycle
- Humming at the end of the cycle but no draining
- Error E24 or E25 (Bosch)
Check these first
The cheapest repair is the one that doesn't need a part.
- Clean the filter assembly at the bottom of the tub.
- Check the drain hose for kinks behind the dishwasher.
- If connected to a disposal, make sure the knockout plug was removed.
- Remove the pump cover and check for glass or debris jamming the impeller.
Step by step
- 1
Cut power and water
Turn off the breaker and the supply valve under the sink.
- 2
Bail the standing water
Remove the filter and use a cup and towels to remove the remaining water.
- 3
Remove the pump
On most Bosch models the pump twists out from inside the sump after the cover is removed. On others, remove the toe kick and access it from below.
- 4
Install the new pump
Transfer the connector, seat the pump and twist until it locks. Replace the cover and filter.
- 5
Test
Restore power and water, run a rinse/drain cycle, and check for leaks.
Questions
- Why does my dishwasher hum but not drain?
- A humming pump that doesn't move water is either jammed by debris or has a failed motor. Clear the impeller first; if it still hums, replace the pump.
- What does error E24 mean on a Bosch dishwasher?
- E24 indicates a drain problem — usually a clogged filter, kinked hose or failing drain pump.