Dishwasher
E23
The E23 error code on a Bosch dishwasher indicates a fault with the drain pump — specifically that the pump isn’t working as expected. It’s a moderately serious fault that will stop your machine completing a cycle, but in many cases it’s something you can resolve yourself.
What does this error mean?
E23 tells you the dishwasher’s control board has detected that the drain pump is not operating correctly — it may be blocked, running but failing to shift water, or failing electrically. Bosch uses this code to distinguish drain pump motor faults from general drainage issues (which typically show as E24 or E25). In short, the appliance suspects the pump itself is the problem, not just a blocked hose or filter.
Est. repair cost
£80–£150 professional repair (parts + labour); £15–£40 DIY drain pump replacement part only
🔍 Likely causes
🛠️ Step-by-step fix
Reset the machine first: switch the dishwasher off at the wall, wait 60 seconds, and restart a short cycle. A one-off control board glitch can trigger E23 and a reset often clears it.
Clean the filters: remove the coarse filter and fine mesh filter at the bottom of the dishwasher, rinse them under the tap, and scrub away any grease or debris. Refit securely — a loose filter lets debris reach the pump.
Inspect the drain pump for blockages: bail out any standing water with a towel or sponge, then unscrew the pump cover at the base of the dishwasher sump (refer to your model’s manual — usually a quarter-turn anti-clockwise). Check the impeller for glass, bones, or debris and carefully remove anything you find.
Check the drain hose: pull the dishwasher out slightly and inspect the corrugated drain hose running to the sink or standpipe. Ensure it isn’t kinked and that the connection at the standpipe is clear. Disconnect and flush if in doubt.
Check your sink trap: remove and clean the trap beneath your kitchen sink. A partial blockage here creates back-pressure that can overload the drain pump and trigger E23.
If none of the above resolves the fault, the drain pump motor itself has likely failed. Replacement pumps for common Bosch models (e.g. SMS, SMV series) are available for £15–£40 online. Turn off the water and power supply before any disassembly, and follow a model-specific guide carefully.
📞 When to call a professional
If you’ve cleared all visible blockages, checked the hose, and reset the machine but E23 returns, the pump motor or its wiring is faulty — call a qualified appliance repair engineer. Tell them: ‘My Bosch dishwasher is showing error code E23, I’ve cleaned the filters and pump impeller and checked the drain hose, so I suspect the drain pump motor or wiring has failed.’ This saves diagnostic time and money.
⚖️ Repair or replace?
A professional repair for a drain pump replacement typically costs £80–£150 including parts and labour in the UK. If your dishwasher is under 5 years old, repair is almost always worth it. For machines over 8–10 years old, weigh repair cost against the £300–£600 price of a comparable new Bosch — if other components are ageing, replacement is often the smarter investment.