Lennox 36M72 Secondary Heat Exchanger

Product Description

The LENNOX 36M72 is a secondary heat exchanger designed for use in gas furnace applications. The secondary heat exchanger sits downstream of the primary heat exchanger in a condensing furnace, extracting additional thermal energy from flue gases before they exit the system. This increases overall efficiency and is a key component in high-efficiency condensing furnace designs. Replacement of a cracked or degraded secondary heat exchanger is typically performed by a licensed HVAC technician as part of a heat exchanger inspection or efficiency-restoration service call.

This part is intended for furnace installations where a secondary heat exchanger is required, typically in condensing gas furnaces operating at higher Annual Fuel Utilization Efficiency ratings. These systems produce condensate as a byproduct of the secondary heat exchange process. The 36M72 serves as an OEM-style replacement component for restoring proper furnace operation when the original secondary exchanger has failed, cracked, or corroded beyond serviceable condition.

Key Features

• Secondary heat exchanger configuration for condensing furnace systems
• OEM-style replacement designed to restore system efficiency
• Weighs 14.0 pounds, consistent with robust heat exchanger construction
• Direct fit for furnace applications requiring a secondary stage exchanger

Compatibility

Designed as an OEM-style replacement secondary heat exchanger for condensing gas furnace systems.

Installation Notes

Installation should be performed by a licensed HVAC technician. Shut down gas supply and disconnect electrical power to the furnace before beginning any heat exchanger service work. Heat exchanger replacement may require partial disassembly of the furnace cabinet and flue connections; follow all applicable local codes and the furnace manufacturer service documentation. Inspect the condensate drain system for blockage or damage any time secondary heat exchanger service is performed.

Technical Specifications

• Type: Secondary Heat Exchanger
• Used On: Furnace
• Weight: 14.0 pounds

Standard Information

• Brand: LENNOX
• Manufacturer Part Number: 36M72