Hoover dual steam plus Manual page 12

Instructions for Use
Warning: Unplug the steamer and let the steamer cool down before you change the accessory.
12.
1. Press the Handle Release Button and remove the steel tube.
2. Remove the Floor Head by pressing the mop head release button.
3. Remove the clean water tank by pressing the Water Tank Release
Button.
NOTE: The tube which transfers water from the Water Tank to the
boiler is weighted down with a brass ball. This is an intentional
design to improve efficiency of water usage.
It is normal for this ball to create a rattling sound inside the Water
Tank during use.
(as a handheld steam mop)