Heil Quaker ICP 1173637 Defrost Sensor

For contractors servicing International Comfort Products (ICP) equipment, the Heil Quaker ICP 1173637 Defrost Sensor is the specific OEM replacement part required to restore accurate thermal monitoring in heat pump systems. This L65-33F defrost sensor is a critical thermistor-based component that triggers the defrost cycle when the outdoor coil temperature drops to a calibrated 33°F. Engineered for durability in extreme environments, it replaces previous part numbers such as HH18HA279A and is compatible across a wide range of brands including Heil, Tempstar, Comfortmaker, and Arcoaire. By providing precise resistance feedback to the defrost control board, this sensor prevents excessive ice accumulation on the outdoor coils, ensuring the unit maintains high performance and energy efficiency during the heating season. This genuine part is designed for a direct-fit installation, allowing technicians to resolve "solid block of ice" failures and irregular cycling issues without the compatibility risks associated with universal aftermarket sensors.

Key Benefits

• Direct OEM Compatibility: Specifically designed for ICP heat pump models, ensuring perfect electrical integration and physical fit on the refrigerant tubing.
• Precise 33°F Calibration: The L65-33F specification ensures the system initiates defrost only when necessary, protecting the compressor and maximizing heat transfer.
• Wide Brand Application: Serves as a standard replacement for Heil, Tempstar, KeepRite, and Day & Night systems, making it a versatile stock item for service trucks.
• System Efficiency: Restores factory-spec defrost timing to prevent energy-draining ice buildup and maintain optimal COP (Coefficient of Performance).

Common Questions

What are the symptoms of a failing defrost sensor?
Technicians typically find the outdoor coil completely encased in ice or notice the system staying in defrost mode too long. A faulty sensor may also cause short-cycling or fail to signal the defrost board when temperatures sit below the 33°F threshold.

How do I test the ICP 1173637 sensor in the field?
Use a multimeter to measure the resistance (ohms) of the thermistor. Compare your reading against the manufacturer's resistance temperature chart; a significantly drifted reading or an "open" circuit confirms the need for replacement.

Can I use this sensor on Carrier or Bryant units?
Yes, because ICP is part of the Carrier family, this 1173637 sensor is frequently cross-referenced and used in many Carrier, Bryant, and Payne heat pump applications that specify the L65-33F sensor.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.