The Rinnai Heat Exchanger Assembly Retrofit Kit 556, part number 204000021, is a genuine OEM replacement heat exchanger kit designed for use with Rinnai RHFE-556 series direct vent furnaces and heating products. It provides the primary internal heat transfer component that captures combustion heat and directs it into the heater’s airflow system while safely containing exhaust gases. This assembly is manufactured to match Rinnai’s original specifications so it installs directly in place of a worn or deteriorated exchanger when servicing the furnace.
This retrofit kit is intended for use during maintenance or repair when the existing heat exchanger shows signs of corrosion, reduced heat transfer effectiveness, or physical deterioration that can impair heater performance. A properly functioning heat exchanger is essential for efficient combustion, stable heater operation, and optimal heat transfer to living spaces. Installation should be performed by a qualified technician following the model’s service instructions to ensure secure mounting, proper sealing, and safe connection to the furnace’s vent and combustion systems.
What’s Included: One (1) Rinnai heat exchanger assembly retrofit kit for RHFE-556 series heating units.
Installation Limits: For replacement use only on Rinnai RHFE-556 series direct vent furnaces; install with power off and ensure all mounting and vent connections are secure to prevent leaks.
Compatibility: Compatible with Rinnai RHFE-556 series furnaces and heating products requiring a heat exchanger assembly retrofit kit.
