A WMF 1100 S filter reminder depends on the water-hardness and capacity settings for the fitted filter. It is not a universal replacement date. The manual’s 200-liter example applies at 10°dKH to the specified tank filter; other hardness values change that capacity. Check the cartridge and measured carbonate hardness before copying a setting from another machine.
Two hardness entries, different jobs
The System menu distinguishes measured carbonate hardness from measured total hardness. The carbonate value is used with the filter configuration. The total-hardness entry can be compared with later readings to monitor changes in the supply.
Use an appropriate carbonate-hardness test or a reading from the water supplier, as WMF directs. Don’t substitute a total-dissolved-solids reading for the named measurement. The manufacturer warns that the wrong hardness setting can contribute to scale buildup and leaking valves.
For a machine with the filter option active, the configuration asks for hardness and capacity. The book’s capacity table belongs to its specified BWT tank filter. It does not establish the service life of every cartridge fitted upstream of a plumbed machine. Check that filter’s own instructions instead of choosing a convenient number to silence a reminder.
What the reminder means
At 25% remaining life, the manual says the remaining service life appears each time the machine is switched on. At zero, the replacement reminder repeats every three hours. A notice that returns later in the shift may therefore be the same unresolved filter task.
Changing the cartridge and confirming the change are separate steps in the Care program. Confirmation is followed by an automatic rinse and air-bleeding sequence. Hot water exits the hot-water spout during that process. Keep the outlet clear and follow the screen through the whole program; don’t confirm a replacement that has not happened.
Record the filter model, measured carbonate hardness and actual replacement date together. If the reminder seems inconsistent with those facts, contact us about the 1100 S and include the displayed message. Avoid altering the capacity solely to extend the countdown.
The WMF service page explains pickup and bench diagnosis. We repair the machine but don’t install water-treatment equipment.
Reference: WMF 1100 S User Manual, North America, Water Filter, Filter Change and System settings.