Aprilaire 4403 Insert 319825-402 Refer to the diagnostic chart

Refer to the diagnostic chart on the furnace blower door

Its M12 female connector ensures a secure

Integrating this HVAC valve repair kit into your maintenance schedule prevents the costly full replacement of the valve body while resolving common bypass or leakage issues

Constructed from high-grade 409 stainless steel

For a complete TJLE assembly

Aprilaire 4403 Insert 319825-402 Refer to the diagnostic chartThe 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