Lennox 73K21 Limit Switch 319847-401 Heavy-Duty Construction: Features zinc-plated steel

Heavy-Duty Construction: Features zinc-plated steel flanges and high-quality DPST contacts rated for up to 2 HP at 230V 1-phase

This time delay relay kit is the direct field-replacement for the obsolete Reznor 116044 and Thermodisc 12530305256 models

Technicians should check for continuity across the coil

using a higher wattage element than specified can trip breakers or damage the internal wiring

Does this board require specific programming in the field

Lennox 73K21 Limit Switch 319847-401 Heavy-Duty Construction: Features zinc-plated steelThe Lennox 73K21 Limit Switch is a critical safety component designed for precise thermal regulation within residential gas furnaces and air handlers. Engineered as a Lennox replacement part, this 145 175F AUTO limit switch monitors discharge air temperatures to prevent heat exchanger overheating. It operates on a normally closed circuit that opens if temperatures exceed the 175F threshold, effectively cutting power to the gas valve or ignition