What F88 Means
F88 is the turbidity sensor problem in Miele’s G-series problem summary. The turbidity sensor measures how dirty the wash water is so that automatic programs can decide how long to run and how many rinses to use; with it out of action the machine loses the input that makes those programs adaptive.
Common Causes of F88
- Turbidity sensor optics fouled by grease or scale
- Sensor electrically failed
- Wiring to the sensor damaged in the sump area
🔧 One Safe Check You Can Try
Switch to a fixed program rather than the automatic one for now — results will be fine, they simply will not be optimized. Also check that the filter combination is clean, because heavy soil carried over from a previous load can confuse an otherwise healthy sensor.
⚠ Why You Shouldn't Go Further Than That
- An optical sensor in a sump can be dirty rather than dead, and cleaning it correctly means getting to it without scratching the optical window.
- The sensor sits in the water path below the filters, so access involves partial dismantling of the sump on a machine that has to be isolated first.
- Replacing a sensor that was only fouled is money spent on a cleaning job.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.
Technical Reference
- Code
- F88
- Appliance
- Miele dishwasher
- Maker documentation
- Miele owner manuals and use & care guides
- Checked
- September 2026
Code meanings can change between control generations. Before acting on a code, match the full model number on your appliance's rating label against the manual for that model. We are an independent repair service, not affiliated with Miele & Cie. KG.