This is an Aprilaire 4217 Humidifier Scale Control Insert replacement for use with the Aprilaire 500 Humidifier Water Panel Evaporator (Aprilaire 10) and the Aprilaire 4218 Humidifier Water Distribution Tray in the following Aprilaire 500 Series humidifiers: Aprilaire 550, Aprilaire 550A, Aprilaire 558 Humidifier and the Aprilaire 568 Humidifier.
The Aprilaire 4217 is a plastic U-shaped humidifier replacement component which encases the Aprilaire 10 Water Panel Evaporator. It is made to redirect any harmful mineral build up back into the evaporator panel and to prevent water from leaving the evaporator section and entering another portion of the humidifier.
This is a genuine factory replacement Aprilaire 4217 humidifier scale control insert also known as the Aprilaire 4217 scale control insert and April Air 4217 scale control insert. The Aprilaire 4217 scale control component should be replaced as needed in your Aprilaire humidifier along with all other Aprilaire 500 parts.