Caleffi NA553379 Boiler Trim Kit 1-1/4" Sweat Tank

The Caleffi NA553379 Boiler Trim Kit is a pre-assembled hydronic assembly used in HVAC boiler systems to streamline the connection of essential control and safety components. It combines an air separator, automatic fill valve, backflow prevention systems, expansion tank, check valve, and connecting fittings into a single configuration. In hydronic heating systems, it regulates system pressure, removes entrained air, and support to maintain stable water circulation within closed-loop boiler circuits. It is installed near the boiler in residential or light commercial HVAC systems applications, where it supports efficient heat distribution to radiators or baseboard systems while ensuring consistent boiler operation and system protection under varying load conditions.