What Error 18x Means
Error 18x tells you that one of your sterilizer's filters is clogged or needs replacement. Your W&H Lisa has two critical filters:
Chamber Filter: Prevents dust & debris from entering the sterilization chamber, located inside or below the chamber.
Bacteriological Filter: Removes bacteria from air during cycles (critical for safety), part of the exhaust system.
When either filter clogs, steam and air can't flow properly, and your sterilizer won't work. Error 18x is your sterilizer's reminder: clean or replace the filter now.
⚠️ Don't Ignore This: A clogged filter means your sterilization cycle won't complete properly. Your instruments may not be fully sterile.
Quick Fix: Clean the Filter (10 Minutes)
- Turn off the sterilizer
- Allow the chamber to cool completely (15-20 minutes)
- Locate the chamber filter—it's usually a small cylindrical mesh or foam component
- Gently remove the filter (don't force it)
- Visually inspect: If it looks clean, reinstall and restart. If dusty/clogged, gently rinse under lukewarm tap water.
- Let it air dry completely (do NOT use heat or compressed air)
- Reinstall the filter—make sure it locks in place properly
- Turn on the sterilizer and restart
💡 Pro Tip: Do NOT scrub or soak the filter. Gentle rinsing is all it needs. Aggressive cleaning can damage the filter material.
Filter Replacement Schedule
Chamber Filter: Every 400 cycles of sterilization. Bacteriological Filter: Every 400 cycles OR 50 months (whichever comes first). Emergency replacement: If filter is visibly damaged, torn, or deformed—replace immediately.
When you see the 400-cycle alert, note the cycle count, order replacement filters from DIA immediately, replace when they arrive, and reset the cycle counter in your sterilizer menu (or contact DIA for help).
How to Replace Your Filters
Chamber Filter Replacement (DIY - 10 Minutes): Turn off and cool. Locate the chamber filter. Gently remove the old filter (most twist out or slide out). Note the orientation. Inspect the filter slot for debris. Insert the new filter in the same orientation. Secure it. Close and restart. Run one empty test cycle.
Bacteriological Filter Replacement (Professional Recommended): The bacteriological filter is part of the exhaust system and requires careful handling. We recommend contacting DIA for professional replacement to ensure proper installation and testing. Improper installation can compromise sterilization safety.
Signs Your Filter Needs Replacement
Filter looks dark, discolored, or dirty even after gentle rinsing. Filter material is cracked, torn, or deformed. Visible buildup or caking on the filter surface. Filter won't hold its shape (material is degraded). Sterilization cycles taking longer than usual. Steam not reaching full pressure. Visible dust or debris in the chamber. Unusual noise or hissing during cycles.
Prevent Error 18x: Monthly Filter Checks
Turn off sterilizer and cool chamber. Visually inspect the chamber filter (no need to remove). Look for visible dust, debris, or discoloration. If it looks dusty, gently rinse it. Reinstall and restart. Make a note in your maintenance log.