Meiko Commercial Dishwasher Error Code 406: Cartridge Near End
Message 406 on a Meiko M-iClean U with a demineralization cartridge is an advance notice that the cartridge is nearing the end of its life. Keep working, order a replacement now, and change the cartridge when message 407 appears.
Low: an advance notice only; the unit keeps washing normally.
- Code
- 406
- Maker
- MEIKO
- Equipment
- Dish machines
- Applies to
- M-iClean U (red/gray messages)
What does MEIKO error code 406 mean?
Machines fitted with a demineralization cartridge use it to strip minerals from the water for the final rinse, which is what gives spot-free glassware. The cartridge has a limited capacity, and as it is used the control counts toward that limit. When the cartridge is close to spent, the display shows message 406, which the manual describes as an advance report, not a stop. Nothing is wrong with the machine at this point. The message exists so staff have time to get a spare before the cartridge actually runs out. After 406 comes message 407, the instruction to change it. How soon that arrives depends on how hard the incoming water is and how many loads the machine washes each day, so a busy bar with hard water may see it sooner than a small cafe. The maker's operator step is to have a replacement cartridge ready. Use the interval between 406 and 407 to place the order, so the change can be done at once when the next message appears.
Affected models and control systems
This applies to Meiko M-iClean U undercounter dishwashers fitted with a demineralization cartridge. Models without that cartridge will not show it, and other Meiko ranges number messages differently.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Message 406 on the display
- No change yet in how dishes look
- A cartridge that has been in service for a long time
Possible causes
Listed in MEIKO's documentation
- Cartridge capacity used up
- Hardness of the incoming water
- How many loads the machine washes each day
- Cartridge supplier and order lead time
Other likely causes — what usually sits behind error code 406 on this control. A technician confirms which one it is before any part is replaced.
- High mineral content in the water, which exhausts the cartridge faster than the last one
- A recent run of banquet or event volume that used up capacity early
Safe checks before calling for service
- Order a replacement cartridge now so one is on hand, as the maker says.
- Keep working. The message is an advance notice.
- Replace the cartridge when message 407 appears.
- Write down the date 406 appeared so you can estimate the next change.
- If you are not sure how to change it, call us and we do it on a visit, with a written price first.
How a technician diagnoses error code 406
- Confirm the message is 406 and not 407.
- Check the cartridge date and the machine's load history with the operator.
- Test incoming water hardness at the supply.
- Check the cartridge connections for leaks.
- Plan the cartridge change and confirm the correct part.
- Changing the cartridge means shutting the water supply and opening the housing, and a poorly seated one leaks into the cabinet.
- Knowing when the cartridge will really run out needs a water hardness reading, which we take with a test kit.
- Resetting the cartridge counter after a change is a control setting that should match the new part.
How error code 406 differs from similar codes
Message 407 is the actual change instruction that follows 406, so 406 is the early warning.
Technical reference
- Document
- M-iClean U Original operating instructions 9763258 (update 2026-06), 9.4.1 Messages p.43-45
- Edition
- 9763258 / Valid from: 2018-09 / Update: 2026-06
- Models / control
- M-iClean U (red/gray messages)
- Section
- 9.4.1 Messages, printed pp. 43-45 of 70 (PDF pp. 43-45)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related MEIKO dish machine error codes
Do I have to change the cartridge now?
No. The maker's step is to get a replacement ready and change it when 407 appears.
How long between 406 and 407?
The manual gives no fixed time. It depends on water hardness and the number of loads per day.
What if I ignore 406?
You will see 407 next, and once the cartridge is spent the glassware starts to spot.
Need help with MEIKO error code 406?
A technician confirms the cause on site and gives you the price in writing before any work starts.