Bosch Dishwasher Error Code E23

Bosch Dishwasher Error E23 — Meaning, Causes, and Fixes

Overview: The E23 error on Bosch dishwashers is typically a drain-related fault indicating the dishwasher cannot empty water properly. It commonly appears when the drain pump is obstructed, the drain hose is clogged or kinked, the garbage disposal connection is blocked, or the pump itself has failed electrically or mechanically. Left unresolved, E23 can lead to standing water in the tub, poor wash and rinse performance, unpleasant odors, longer cycles as the machine retries draining, and in some cases water damage or electrical stress if the fault is persistent.

Why it occurs: E23 arises when the control electronics detect an abnormal condition while attempting to pump water out. This can be caused by physical blockages that prevent the pump impeller from turning, foreign objects jamming the pump, a clogged filter or sump preventing flow, a plugged drain hose or disposal connection, or an electrical failure either in the pump motor or its wiring. Moisture or corrosion in the pump area and a faulty control board or sensor can also trigger the code.

User impact: Users usually notice standing water after a cycle, partial or poor cleaning results, persistent foul smells from old food and water, repeated error codes that interrupt cycles, and longer-than-normal washing or draining times. If ignored, the issue can escalate to water overflow, increased risk of leaks, and potential damage to internal components, which increases repair cost.

Common Causes

• Clogged or dirty filter and sump area
• Foreign objects lodged in the drain pump or impeller (glass, food debris, broken crockery, labels)
• Blocked or kinked drain hose
• Garbage disposal knockout plug not removed or disposal blockage
• Faulty or seized drain pump motor
• Stuck check valve or clogged air gap
• Wiring connections loose, corroded or damaged between pump and control board
• Faulty control board or pump relay
• Float switch or water sensor issues causing false drain fault signals

Troubleshooting Steps

1. Power down and isolate the dishwasher for safety. Turn off the mains and shut the water supply before accessing internals.
2. Remove the bottom rack and access the filter assembly. Clean the filter, microfilter and sump of food debris and gunk. Inspect the filter for cracks or wear.
3. Visually inspect the sump and pump area for foreign objects. Remove any debris that could jam the impeller.
4. Manually check the drain pump impeller for smooth rotation. If it is stuck, clear obstructions or consider pump replacement if the impeller is broken or seized.
5. Inspect the drain hose for kinks and blockages. Disconnect the hose and flush it with water to ensure full flow. Also check the air gap and garbage disposal connection for obstructions.
6. Verify the garbage disposal knockout plug has been removed if the dishwasher was recently installed into a sink with a new disposal.
7. Check wiring and connectors at the pump and control board for corrosion, loose pins, or damaged insulation. Re-seat connectors securely.
8. Run a diagnostic/drain test program if your model supports it to confirm pump operation and isolate the fault code behavior.
9. If the pump hums but does not pump or the impeller will not turn freely, replace the drain pump assembly. If the pump does not receive voltage during a drain cycle, suspect the control board or wiring.
10. After repairs or cleaning, restore power and run a short cycle to confirm the E23 code is cleared and the dishwasher drains normally. Monitor for leaks and unusual noises.
11. If you encounter signs of water damage, persistent electrical faults, or the problem returns after replacing the pump, call a qualified appliance technician to diagnose control board or sensor failures.

Maintenance and Prevention Tips

• Clean the filter and bottom of the tub at least once a month to prevent buildup.
• Empty food containers and scrape plates before loading to reduce debris entering the drain.
• Run hot water at the sink before starting the dishwasher so the cycle begins with hot supply water.
• Flush the drain hose periodically with hot water or a vinegar solution to dissolve grease.
• Avoid placing small items or loose objects in the dishwasher that could fall into the sump or pump.
• Check and remove the garbage disposal knockout plug at installation time and clear the disposal of blockages regularly.
• Inspect hoses annually for kinks, clogs, or soft spots and replace if deteriorated.
• Use the recommended detergent to avoid excessive suds that can interfere with draining.
• Run a dishwasher cleaner designed to remove limescale and grease every 1-3 months.
• Ensure proper dishwasher installation with correct hose routing and no sharp bends in the drain line.
• Replace worn or damaged filters as required by the manual.
• Do not overload the dishwasher; allow water to reach the drain and pump area unobstructed.
• Periodically inspect the air gap (if present) and clear any debris.
• Listen for abnormal pump noise and address it promptly before it fails.
• If you have hard water, consider a water softener to reduce scale buildup that can affect valves and pumps.

FAQs

Conclusion and Safety Notice

The E23 error is usually related to the dishwasher’s ability to drain and is often fixable without expensive parts by cleaning filters, removing foreign objects, and clearing the drain hose or disposal. However, because draining components live near water and electrical parts, always isolate power and water before inspecting or attempting repairs. If you are unsure, encounter signs of electrical failure, or the code persists after basic troubleshooting, contact a qualified appliance technician. Prompt, safe action will prevent water damage and extend the life of your Bosch dishwasher.

For best results, follow the maintenance tips above and consult your model’s manual for model-specific diagnostic procedures. When in doubt, hire a trained professional to avoid injury or further damage.