Dyson humidifier displays F3 and will not start misting, fan may still run briefly

Safety first: Unplug the unit and remove the water tank before inspecting the base.

• 1. Confirm water level: Ensure the tank is properly filled and seated. Some Dyson humidifiers require the tank cap to be fully tightened to actuate internal valves.
• 2. Clean level sensor area: Look into the base for the water level sensor (often a small float, magnetic switch, or metal probes). If you see slime or mineral deposits, clean with a soft brush and a 1:1 vinegar-water solution. Rinse and dry thoroughly.
• 3. Check float movement: If your model uses a float, gently move it up and down. It should move freely without sticking. If it is jammed, clean the guide and remove any debris.
• 4. Reseat tank: Reinstall the tank carefully, ensuring it locks into place. Some models have a micro-switch that detects tank presence; make sure the tank is fully engaged.
• 5. Persistent F3: If the error remains, the level sensor or its wiring may be faulty and require replacement. This typically involves opening the base and should be done by a technician.