Bosch Greenstar Concentric 40" Extension

Bosch Greenstar Concentric 40" Extension (PN 7738003240) is a factory-compatible concentric flue extension for Greenstar boiler venting systems, providing an additional 40 inches of run to accommodate through‑wall or roof penetrations. It is intended to integrate with Bosch Greenstar concentric vent components to simplify alignment and sealing during field installations, making it suitable for professional installers and HVAC service technicians. Note: I searched Bosch North America sites (Bosch Home Comfort / Bosch Climate) and did not find a dedicated product page or parts diagram for PN 7738003240; the description above is derived from the part name and its role within Greenstar concentric venting systems. (bosch-homecomfort.com)