Water left in the bottom of a dishwasher is almost always a blocked filter or a blocked drain path — both are safe to check yourself.
Likely causes, ranked
- Blocked filter in the tub floor Most likely — Food debris collects in the cylinder filter; rinse it under the tap.
- Blocked drain hose or sink spigot Likely — A blocked kitchen sink or trap backs up into the dishwasher hose.
- Blocked drain pump impeller Likely — Glass shards or seeds jam the impeller (Bosch E25).
- Failed drain pump Less likely — If the path is clear and the pump makes no sound, it has failed.
First checks
- Unplug or switch off at the socket.
- Remove the filter cylinder in the tub floor and rinse it under the tap.
- Check the kitchen sink drains freely — clear the trap if not.
- Check the drain hose at the sink connection for kinks or blockage.
- Run a Rinse programme and watch the sump empty.
Safety
Unplug before reaching into the tub. Beware of broken glass around the pump area — use a torch, not fingers.
Call a professional when…
Call a professional if the sump still holds water after filter and hose checks — the pump needs testing or replacing.