Guide
Dishwasher Not Draining: Safe Checks Before Calling an Engineer
A practical guide to the safe first checks when a dishwasher will not drain properly or leaves water in the base.
Check the accessible filter, visible hose route, and sink or waste connection before arranging repair, but stop if water remains, the fault returns, or any leak or electrical concern appears.
Last updated: 17 June 2026
A dishwasher that will not drain is often dealing with a restriction somewhere in the drainage path. Food debris, labels, grease, a kinked hose, or a blocked sink waste can all stop water leaving the appliance properly.
Common signs of a dishwasher drainage problem
- Dirty water remains in the bottom of the dishwasher after the cycle stops.
- The drain pump runs for longer than usual or sounds strained.
- The programme stops around a drain stage.
- Drainage-related codes such as Bosch E24, Bosch E25, Bosch E23, or Samsung 5C appear.
Safe first checks
- Switch the dishwasher off and unplug it, or isolate it at the wall or breaker, before checking accessible parts.
- Remove and clean the user-accessible filter, then refit it securely as the model manual describes.
- Look for visible food debris, labels, or grease in the sump area, but do not reach blindly because sharp glass can be hidden.
- Check the visible drain hose for kinks, trapped sections, or a route that has been pushed awkwardly behind the appliance.
- Check the sink spigot, standpipe, or waste connection if the dishwasher drains into it and the connection is safely accessible.
If the dishwasher is integrated, heavy, or hard to move safely, keep checks to what you can reach without forcing the appliance out. A drainage fault is not worth risking a leak, damaged flooring, or an unsafe electrical situation.
What not to dismantle
- Do not dismantle the drain pump, motor, heater, wiring, control board, side panels, base tray, or sealed components.
- Do not test live wiring or bypass safety devices.
- Do not keep restarting the dishwasher while standing water remains inside.
- Do not continue normal use if water appears underneath the appliance or a leak-protection code appears.
When to call an engineer
- The same drainage code returns after the filter, visible hose, and waste connection checks.
- Water remains trapped in the appliance after one short drain or rinse test.
- The pump hums, grinds, or sounds strained.
- There is water underneath the dishwasher, a burning smell, tripped electrics, or any concern about water reaching electrical parts.
- The next step would require removing panels, opening sealed parts, or dismantling the pump.
Dishwasher drainage fault codes
Bosch Dishwasher E23
The dishwasher has detected a drain pump fault or blockage.
Bosch Dishwasher E24
The dishwasher is not draining properly.
Bosch Dishwasher E25
The drain pump area may be blocked or unable to move water properly.
Samsung Dishwasher 5C
The dishwasher is not draining properly.
Bosch Dishwasher E22
the filter or sump area is dirty, blocked, or restricting drainage.
Dishwasher leak and overflow warnings to compare
Samsung Dishwasher LC
Leak protection has been triggered.
Samsung Dishwasher OC
the dishwasher has detected an overfill or water-level problem.
Bosch Dishwasher E15
The dishwasher anti-flood system has been triggered
Bosch Dishwasher E30
the dishwasher has detected a water safety, leak, or overfill-style problem.
Frequently asked questions
Why is my dishwasher not draining?+
A dishwasher may not drain because the accessible filter, sump area, drain hose, sink spigot, standpipe, or waste connection is blocked or restricted.
Can I run the dishwasher again if water is still in the bottom?+
No. Clean the accessible filter and check the visible drain route first. If water remains after one short drain test, stop and arrange diagnosis.
Should I dismantle the dishwasher pump to clear a blockage?+
No. Keep checks to user-accessible parts described in the manual. Dismantling pumps, wiring, panels, or sealed components should be left to an engineer.