the 542A is the specified replacement for the 542ASF and 98171

providing high-accuracy feedback to the burner and circulator circuits

ensuring the low-level compressor runs during moderate demand and both compressors engage during high demand

Designed specifically for ducts spanning 2 feet to 4 feet in width

Lennox 10W89 Piston Kit 323269-701 the 542A is the specifiedFor service technicians maintaining Lennox air conditioning and heat pump systems, the Lennox 10W89 Piston Kit (100484 37) is a critical fixed orifice metering device required to regulate refrigerant flow. This genuine OEM Lennox 10W89 kit features a precise 0. 090 orifice size, ensuring the evaporator coil receives the exact refrigerant saturation needed for optimal heat exchange. Whether you are performing a piston orifice replacement during a coil