The Rinnai Ext. Kit M 21"-40", part number FOT-156, is a direct vent extension kit designed to extend the exhaust and intake venting for compatible Rinnai direct-vent wall furnaces and heaters. This adjustable kit provides a vent extension range from approximately 21 inches up to 40 inches to help reach required termination locations or adapt to installation constraints. It is engineered to match the original equipment venting components so it integrates into the certified vent system with secure connections and proper alignment.
This extension kit is typically used when the standard vent run from the heater does not reach the outside termination point, or when additional length is needed to navigate around structural obstacles while maintaining safe airflow. It includes both the exhaust pipe and intake hose components needed to extend the venting system while preserving the balanced intake/exhaust design of the direct vent configuration. Proper installation according to the manufacturer’s venting instructions helps maintain correct clearances, secure fittings, and balanced airflow for safe operation.
What’s Included: One (1) Rinnai vent extension kit adjustable from approximately 21" to 40".
Installation Limits: For use only with compatible Rinnai direct-vent heaters requiring a vent extension; install as part of the certified vent system and maintain required clearances and secure connections per instructions.
Compatibility: Compatible with Rinnai direct-vent models such as EX11CT and EX11DT that accept an adjustable 21"-40" vent extension kit.
