The Lennox 42J04 is the current OEM replacement and is physically and technically identical to the 42J0401 model

a blocked secondary heat exchanger

Can this knob be used on other brands of HVAC controls

Using an incorrect differential can lead to heat exchanger damage or improper fan operation

Reznor 129853 Fan Blade The Lennox 42J04 is theThe Reznor 129853 is a precision engineered 10 inch axial fan blade designed specifically for compatible Reznor unit heaters and HVAC systems. Featuring a 5 blade configuration, this component is balanced to maintain optimal airflow across the heat exchanger while minimizing motor strain and operational noise. When replacing a damaged or pitched blade, ensuring an exact OEM Reznor replacement part match is critical for maintaining the designed static