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

ensuring the internal trim remains aligned under high-pressure conditions

wide-contrast color change—green for dry and yellow for wet—protected by a filter pad and screen to prevent contamination and turbulence from affecting readings

always use the 350F rollout switch specified by the manufacturer

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

Heil Quaker ICP 1320331 Limit Switch replacing the evaporator scale padThe 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