Maintaining optimal airflow in your unit heater is critical for thermal efficiency and motor longevity

ensuring long-term fan proving switch reliability

Universal Compatibility: Fits most standard Imperial and aftermarket manifolds requiring a 1/8" MPT back mount connection

Verify the resistance across the Lennox 57M67 terminals using a multimeter while the inducer is running

Use a calibrated manometer to measure the actual pressure generated by the inducer

Emerson Alco 056819 Expansion Valve 30067439-890 Maintaining optimal airflow in yourThe Emerson Alco 056819 Expansion Valve (Model HFES 8 HCA) is a high performance, balanced ported valve engineered specifically for heavy duty commercial refrigeration and 8rd party heat pump applications. Utilizing a straight body design with 5 8" x 7 8" ODF sweat connections, this externally equalized valve ensures precise refrigerant flow control by compensating for pressure drops across the evaporator. It is optimized for R22 and R407C systems,