The Heil Quaker ICP 1185790 Defrost Board is a critical electronic control designed for precise heat pump defrost cycle management. This OEM replacement part monitors refrigerant coil temperature and compressor run time to initiate defrost sequences, preventing evaporator coil icing and maintaining system efficiency in low-ambient conditions. Engineered for ICP HVAC equipment, this control board handles the reversing valve solenoid switching and outdoor fan motor cycling. Its solid-state design ensures reliable timing intervals (typically 30, 60, or 90 minutes) and integrates seamlessly with existing 24V control circuits. For technicians performing HVAC troubleshooting, this board facilitates accurate diagnostic testing of the defrost curve. Ensure proper terminal connections to the defrost thermostat (sensor) to prevent short-cycling or inefficient heating performance. Utilizing genuine ICP replacement parts like the 1185790 ensures electrical compatibility with the original manufacturer specifications and preserves the integrity of the heat pump circuit.

• Direct OEM Replacement: Ensures exact fit and electrical alignment for Heil Quaker ICP heat pumps.
• Optimized System Efficiency: Accurately manages defrost cycles to minimize supplemental electric heat usage.
• Engineered Durability: Solid-state architecture resists vibration and thermal stress common in outdoor condensing units.
• Reliable Logic: Prevents frost buildup on the outdoor coil, protecting the compressor from liquid slugging.

How do I verify if the 1185790 board is malfunctioning?
Technicians should check for 24V power at the board and test for continuity across the defrost thermostat leads. If the coil is heavily iced and the board fails to energize the reversing valve or stop the outdoor fan when the sensor is closed, the board likely requires replacement.

Can this board be used on other heat pump brands?
While some defrost control boards share similar logic, the 1185790 is specifically calibrated for ICP units (Heil, Tempstar, Comfortmaker). Always match the part number to the specific unit model to ensure the timing intervals and pin configurations are correct.

What causes these boards to fail prematurely?
Voltage surges, moisture intrusion in the control box, or a faulty reversing valve solenoid drawing excessive amperage can damage the onboard relays. Inspect all wiring for brittle insulation or loose connections during installation.

Item is Non Cancelable / Non Returnable

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.