Bosch Dishwasher Error Code E16

Bosch Dishwasher Error Code E16 — What It Means

The Bosch E16 error code typically appears when the dishwasher detects a problem related to draining or the drain pump circuit. When your Bosch displays E16 it usually means the pump is blocked, jammed, mechanically failed, or the control system is reporting a pump-set/drain issue. This leads to poor water removal from the tub and can cause longer cycles, incomplete washes, poor drying performance, unpleasant odors from standing water, and in some cases water overflow or leakage risk if the unit cannot clear water properly. Users may also notice unusual humming, gurgling, or clicking noises during the drain phase. Addressing E16 promptly helps avoid damage to internal components and prevents standing water that can promote mold and odor.

Common Causes

• Clogged or dirty sump/filter assembly preventing water from reaching the pump
• Foreign objects (glass, food debris, small utensils) jamming the pump impeller
• Blocked or kinked drain hose or clogged household drain connection
• Faulty or failing drain pump motor (electrical failure, worn brushes)
• Defective check valve or anti-backflow valve preventing proper discharge
• Damaged or loose wiring between pump and control board
• Control board (PCB) reporting incorrect pump status or failing to power the pump
• Float/level sensor or leak detection (AquaSensor) issues that misreport water state

Troubleshooting Steps

1. Power down and ensure safety: Turn off the dishwasher at the mains (or unplug) and shut off water supply before any inspection. Safety first — never work on a powered appliance.
2. Remove and inspect filters & sump: Open the door, remove the bottom rack, take out the filter assembly and inspect the sump area for debris, broken glass, and food particles. Clean thoroughly and reassemble.
3. Check for foreign objects: Manually inspect the pump area (after isolating power) for stuck utensils, glass shards, or large debris that can jam the impeller.
4. Clear the drain hose: Inspect under the sink for kinks or clogs in the drain hose. Disconnect and flush the hose to ensure a clear pathway to the household drain.
5. Inspect the check valve: If accessible, check the check valve for blockages or damage. Replace if it’s cracked or failing to open/close properly.
6. Listen for the pump: With power safely restored and door closed, start a drain cycle and listen — a humming without rotation often indicates a jam or failed motor, while silence could indicate electrical fault.
7. Run a diagnostic/service mode: Many Bosch dishwashers have a service mode to run the drain pump. Consult your manual for the key sequence to activate diagnostics and observe error logs or pump behavior.
8. Test pump electrically (advanced): If comfortable, check pump wiring and test continuity with a multimeter. A lack of continuity or out-of-spec resistance suggests a faulty pump motor and replacement is needed.
9. Inspect wiring and connectors: Look for burnt, loose, or corroded connections between pump and control board. Repair or replace damaged harnesses.
10. Reset the dishwasher: After cleaning and checking connections, try a full power reset (power off for 5–10 minutes) and re-run a cycle to see if E16 clears.
11. When to replace parts: If the pump motor shows no rotation after removing obstructions or the motor fails electrical tests, replace the drain pump. If wiring and pump are fine but the error persists, consider the control board as the next suspect.
12. Call a professional if unsure: If steps above are outside your comfort level (accessing pump, electrical testing, control board replacement), contact a certified Bosch technician.

Maintenance / Prevention Tips

• Clean the filter and sump weekly (or per Bosch’s recommended schedule).
• Rinse and scrape dishes before loading to reduce large debris entering the pump.
• Remove and inspect spray arms monthly to ensure no blockages affect circulation.
• Avoid placing small items (like broken glass or small utensils) in the bottom tray where they can fall into the pump.
• Use recommended detergents and avoid overfilling detergent dispensers to reduce residue buildup.
• Run a maintenance cycle with dishwasher cleaner or a vinegar rinse monthly to remove grease and mineral deposits.
• Ensure the drain hose is properly routed with no kinks and the sink trap is clear.
• Install a high loop or air gap on the drain hose per installation instructions to avoid backflow.
• Check door seals and base pan for leaks periodically to prevent water reaching the leak sensor.
• Inspect electrical connections behind the toe panel annually for corrosion or looseness.
• Replace worn pump impellers or housings at the first sign of damage rather than waiting for failure.
• Don’t overload the dishwasher; proper loading improves drainage and cleaning.
• Ensure water hardness is managed — scale build-up can impair pump and valves.
• Securely close the door and ensure the latch is intact to keep cycles running properly.
• Keep the installation area clear for service access so technicians can inspect components easily.
• Follow Bosch service intervals and firmware/service notices if provided by Bosch Home Connect (if applicable).

Frequently Asked Questions (FAQs)

Q: My Bosch shows E16 and there is water in the tub. Can I still run the dishwasher?
A: It’s not recommended. If the unit cannot drain properly you’ll likely get standing water, poor wash/dry results, and risk of leaks. Try clearing filters and running a short drain cycle after power-reset. If unresolved, stop using the machine and troubleshoot or call a pro.

Q: I cleaned the filter but E16 still appears. What next?
A: After cleaning the filter, check the pump area for foreign objects and the drain hose for obstructions. If those are clear, listen for pump operation during a drain cycle. If the pump hums but does not spin or is silent, the pump motor or wiring may be faulty.

Q: Is E16 dangerous or urgent?
A: E16 is generally a medium-severity issue — it won’t normally cause immediate danger, but it can cause flooding or mold if left untreated. If you smell burning or see leaking, unplug the appliance and call service immediately.

Q: Can I replace the drain pump myself?
A: If you are comfortable with appliance repair, basic hand tools, and electrical isolation, you may replace the drain pump. However, you should ensure the correct part number and follow safety precautions. If unsure, hire an authorized Bosch technician.

Conclusion & Safety Notice

Addressing Bosch E16 promptly minimizes the risk of water damage and helps restore proper dishwasher performance. Always disconnect power and water before attempting inspections or repairs. Some troubleshooting steps (electrical testing, pump replacement, control board diagnostics) require technical skill and proper tools — if you are not confident, contact a Bosch-authorized service technician. Professional technicians can safely diagnose electronic faults and perform repairs under warranty-friendly procedures.

If you’ve tried basic cleaning and resets and the error persists, or if you encounter leaks, burning smells, or visible electrical damage, stop using the dishwasher and schedule professional service. Proper diagnosis and repair protect your appliance, your home, and your safety.