Rinnai 11i/17i/HD55i Flue Extension – 500mm (AWF50-05) The Rinnai AWF50-05 500mm Flue Extension is designed to extend the horizontal or vertical flue run of Rinnai 11i, 17i and HD55i non-condensing gas water heaters. This extension is ideal for installations that require longer venting distances, ensuring safe and efficient discharge of combustion gases. Manufactured to Rinnai's quality standards, this 80/125mm coaxial flue extension maintains full system compatibility and compliance with manufacturer guidelines. Perfect for indoor or confined-space installations where standard flue lengths are insufficient. Key Features & Benefits: 500mm Extension Length: Adds extra reach to your flue system for flexible installation. Compatible with Rinnai Models: