Error Code: F18 Difficulty: Moderate
Problem: Water drain time exceeded; blockage in the filter or drainage system.
How to Fix F18 Error (Step-by-Step)
- Unplug the washer from the power outlet for safety and confirm the error stays cleared during a full test cycle.
- Locate the small service door on the bottom front of the washer, and place a shallow pan and a towel in front of it to catch any residual water.
- Open the service door and slowly unscrew the pump filter cap, allowing the water to drain into the pan. Be prepared for up to a gallon of water.
- Once drained, completely remove the filter and clean it of any debris like lint, coins, or buttons. Also, check the filter housing for any obstructions.
- Reinsert the clean filter and tighten the cap securely. Restore power to the washer and run a short drain or spin cycle to check for leaks and see if the error is cleared.
- If the error persists after cleaning the filter, the drain hose behind the washer may be kinked or clogged. Carefully pull the washer away from the wall to inspect and straighten the hose. Disconnect it from the drainpipe to check for and clear any blockages.
- If the filter and hose are clear and the problem continues, the drain pump itself may have failed and will likely need to be replaced.
- Turn the appliance off, wait about 2 minutes, then turn it back on.
What to Check Next on This Bosch Washer
Bosch Washer Error F18: Use the code or symbol as the starting clue, then confirm the actual symptom before ordering parts.
- Unplug the washer before touching wiring, the lock, the pump area, or the control panel.
- Check the door lock, drain filter, inlet supply, and visible harness connections before replacing controls.
- If the code returns during the same part of the cycle, match the repair path to that stage: fill, wash, drain, spin, lock, or control response.
If the issue returns after these checks, match replacement parts to the complete Bosch model number from the appliance tag. The same code can point to different components depending on the exact model and when the failure appears.
Recommended Parts to Check
No exact official OEM part number is listed here because the correct Bosch washer part can vary by complete model number. These are targeted part-category searches, not universal fit claims.
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Bosch washer electronic control boardCommon replacement category: Main control boardFit note: Exact OEM part number varies by full Bosch washer model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for control and communication faults after wiring and connector checks. -
Bosch washer user interface control panelCommon replacement category: User interface / display boardFit note: Exact OEM part number varies by full Bosch washer model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for display, button, selector, or cycle-control faults. -
Bosch washer drain pump assemblyCommon replacement category: Drain pumpFit note: Exact OEM part number varies by full Bosch washer model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for drain, no-spin, and water-removal symptoms after filter and hose checks.
Before ordering: match the part to the complete Bosch washer model number on the appliance tag.
Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.
More options (for a better recommendation)
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When It’s Better to Replace Than Repair
Sometimes replacing an appliance makes more financial sense than putting more money into repairs.
Here are a few signs it may be time to shop for a new one:
For repair parts, verify exact fit with the full washer model number before buying; these links are general replacement-appliance shopping options.
- ✓Appliance over 8-10 years old
- ✓Repair cost over 50% of replacement
- ✓Multiple recent breakdowns
- ✓Major component failure
Recommended Replacement Options
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Expert: Mike Sullivan
EPA Section 608 Certified Technician with 18+ years experience.
Read Editorial Standards →Browse all Bosch error codes: Bosch Error Codes
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