What this error means
Turbidity sensor fault — the water clarity sensor is not reading correctly
The F07 error means the turbidity sensor — which measures how dirty the wash water is so the dishwasher can adjust its programme — is not functioning correctly. This is most commonly caused by the sensor window or the surrounding sump area becoming coated with food residue, grease, or limescale. A blocked filter that prevents water from reaching the sensor, or a wiring fault, are less common causes.
What you'll need first
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Step-by-step
Symptoms to look for
- F07 displayed during the wash or rinse phase
- Cycle runs for much longer than normal before completing or faulting
- Dishes not coming clean — machine not adjusting wash intensity correctly
- Error appears more frequently when using heavily dosed powder or gel detergent
How to fix it
Unplug the dishwasher and remove the lower basket. Unscrew the cylindrical filter anti-clockwise and lift it out, then lift out the flat fine mesh filter beneath it. Rinse both under warm running water, scrubbing the mesh surfaces with an old toothbrush. Pay particular attention to the fine mesh — grease and food particles that pass through the coarse filter collect here and prevent properly filtered water from reaching the turbidity sensor.
With both filter parts removed, look down into the sump cavity. The turbidity sensor is typically a small rectangular or cylindrical component with a transparent or translucent optical window, mounted in or near the sump wall. Using a clean, damp cloth or a soft toothbrush, gently wipe the sensor window and the surrounding area to remove any grease film, food residue, or limescale deposits.
Add a proprietary dishwasher descaler or two tablespoons of citric acid to the base of the tub and run a full 65-degree cycle with nothing else in the machine. Limescale and grease build up gradually on the sensor window and the optical beam it uses to read water clarity becomes progressively more blocked, eventually triggering F07.
Excess detergent — particularly powder or gel dosed for hard water in a soft water area — produces heavy foam that fills the sensor area with bubbles, blocking the optical reading entirely. After the descale cycle, switch to a dishwasher tablet that matches your water hardness, or reduce your powder or gel dose to the level appropriate for your water softness setting.
With the dishwasher unplugged, remove the lower kickplate panel. Locate the wiring connector to the turbidity sensor and check that it is fully seated with no corrosion or moisture on the pins. Disconnect and firmly reconnect it.
Replace the filter assembly firmly, replace the lower basket and run a standard programme with a normal load. The dishwasher should proceed through each phase — fill, wash, rinse, dry — without displaying F07.
When to call an engineer
- Turbidity sensor reads open circuit on a multimeter after cleaning and descaling
- Sensor window is physically etched, opaque, or cracked and cannot be restored by cleaning
- Wiring to the sensor is damaged, corroded, or the connector cannot be seated correctly
- F07 returns within 2 to 3 cycles after a full clean and descale — sensor needs replacing
Frequently asked questions
What does the turbidity sensor do in a dishwasher?
Can using too much detergent really cause F07?
Will a dirty filter cause F07 even if the sensor is clean?
How often should I top up dishwasher salt?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Turbidity Sensor | £20 - £25 | 🛒 Amazon UK → |
| Turbidity Sensor | £20 - £25 | 🏷️ eBay UK → |
| Pressure Switch | £15 - £20 | 🛒 Amazon UK → |
| Pressure Switch | £15 - £20 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.