Over time your Harmony XL system will loose water every time you attach or detach your hand-piece. A few drops most of the time. It’s good to fill your system at least once a year with water just to make sure that the reservoir is always topped off but if you experience a flow switch error or you experience a low water level error, it’ll pop up on the screen and it’ll tell you that you have to fill it with water. In that case, you have to fill it.
In order to fill your machine, you’re going to have to insert this funnel fitting into the fill port right here. Only fill your machine with deionized or distilled water only. Never tap water. You have the vent fitting right here and put it into the vent port. You’re going to be filling this funnel up with water and once water comes out of the vent fitting, that’s how you know that the system is filled. See. The system is now filled with water. Here you go. Disconnect that. Disconnect the fill kit right here and you are good to go.