Aprilaire 4403 Insert 319825-402 Constructed from high-grade 409 stainless

Constructed from high-grade 409 stainless steel

Leak-Proof Seal: Utilizes a specialized Teflon gasket within the rotolock housing to ensure a gas-tight seal under high-pressure conditions

utilizing a standard 1/4-20 threaded shaft for seamless integration with existing fan blades

ensuring the necessary capacitance 4uF rating for stable motor starting and continuous run performance in demanding commercial and industrial environments

Engineered specifically for pneumatic thermostat systems

Aprilaire 4403 Insert 319825-402 Constructed from high-grade 409 stainlessThe Aprilaire 4403 Scale Control Insert is a critical humidifier replacement part engineered specifically for the Aprilaire Model 400 series, including the 400A and 400M. This U shaped component serves as the structural frame for the water panel, ensuring it remains properly positioned for optimal evaporation. Designed with a built in float chamber, the 4403 manages water levels effectively to prevent internal leakage and overflow. Its primary