Product review (5 stars): Affordable kit to help your Aprilaire humidifier keep dry winter air at bay.
We have an Aprilaire 550 attached to our furnace, all of which was installed in 1999. We are the second owners of our home, and aside from replacing the water panel every year, the other parts of the humidifier this kit replaces are original. The humidifier wasn't giving us any problems, so this kit was strictly preventive maintenance. Everything is simple to replace (if you need help, there are plenty of online instructional videos out there). The one thing I noticed was that the tiny strainer that goes into the inlet of the solenoid is colored red, as opposed to the black one on the product photo. No issues with it, however.

The good thing is, once you install this kit, you only need to replace the water panel every year. Aprilaire recommends this kit to be changed out every five years or so.