The Aprilaire maintenance kit 4788 includes everything you need to make your Aprilaire Model 400, 400A, 400M like new.
This 400 Series kit includes one each of the following items:
The Model Number on the Model 400 400A 400M is located on the side with the solenoid valve. The Aprilaire 400 Series can be configured with the bypass duct on the right or left. Thus the soleniod and label can be located on the right or left side.Â
Aprilaire Flow-Thru humidifiers have a solenoid with a small strainer filter in the body. These strainers should be inspected and cleaned when replacing the water panel. If the strainer becomes clogged the water pressure will tear it and pieces will jam the solenoid or loose pieces will block the orifice.