this mercury-free thermostat is the direct technician-recommended upgrade

replacing the evaporator scale pad annually is essential to prevent mineral scale buildup

If the inducer is running and your manometer reads above 0

Is this compatible with non-McDonnell & Miller controls

preventing hazardous accumulation in the mechanical room

Heil Quaker ICP 1320331 Limit Switch this mercury-free thermostat is theThe Heil Quaker ICP 1320331 Limit Switch is a critical OEM replacement part designed for precision temperature regulation in ICP furnaces and high performance HVACR systems. Engineered with a factory calibrated 120 160F temperature range, this auto limit switch functions as a primary safety control, monitoring the thermal environment of the heat exchanger. When temperatures reach the upper 160? F threshold, the contacts open to interrupt the burner