The ironing board is not in the lowest working position.

Turn and hold the rotary control in the direction (arrow symbol).

Press the tower down into its lowest working position.

Turn the rotary control in the direction (lock symbol) and then let go of it again.
The ironing board unlocks and moves down.

Guide the ironing board downwards or allow it to slide down by itself.

Press the tapered end of the ironing board upwards until it engages with the tower.
Press the ironing board leg against the tower until it engages.