1. unplug Zoe
2. empty Zoe's water tank and rinse with warm water
3. plug Zoe in again
4. first press and hold the LED button and then also press the ON/OFF button
5. press and hold both buttons for approx. 2-3 seconds
6. the LED should then flash 2 times
7. refill Zoe with water and start.
Or: Descale overnight and clean the membrane with an ear swab. Also descale more often, I do this every 2 weeks. Hope it helps