Descale the humidification filter when the first speed light (with the indication CLEAN 1/5 above it) flashes.
To descale the humidification filter, first take it out from the water tank (Note: you have to remove the water bucket first before you can remove the water tank).
Then mix white vinegar (5ml/100ml acetic acid) with an equal amount of tap water in a container that is large enough to soak the humidification filter in. If there are white deposits (scale) on the filter, make sure the side with the white deposits is immersed in the water. Soak the humidification in the vinegar solution for 1 hour.
After soaking, discard the water-vinegar solution.
Rinse the humidification filter under the tap to rinse away the vinegar residues. During rinising, turn it so that both sides are rinsed.
Then drip off the excess water from the humidification filter and put it back into the water tank.