Always replace a blue/green control limit with the same color-coded part to ensure the safety thresholds match the original equipment design

Always cross-reference the part number on the existing board to ensure a match for voltage and terminal configuration

economizer linkage

it needs replacement

For facility managers and HVAC contractors

Lennox 75W43 Thermal Switch 323080-701 Always replace a blue/green controlThe Lennox 75W43 is a high precision compressor thermal switch engineered for critical temperature regulation in industrial and residential HVACR systems. As a genuine OEM component (Manufacturer Number 103048 01), this HVAC thermal protection switch prevents catastrophic equipment failure by monitoring operational heat levels. It features a specified open temperature range of 239F to 257F, which interrupts the electrical circuit to protect the