The Part L Compliant Straight Combi Filling Loop is a ready-to-install assembly designed for safely topping up sealed central-heating systems in accordance with current Building Regulations Part L. Featuring a straight braided hose, lever-operated isolation valve, and a WRAS-approved double check valve, it ensures secure backflow prevention and controlled system filling. Supplied with 15mm compression connections and optional blanking caps (depending on model), it provides a reliable, regulation-compliant solution for combi boiler maintenance and installation.