Built for non-reversing operation

single-temperature controller features a horizontal mount configuration and a standard 55-85°F dial range for precise setpoint management

Standard field testing involves checking for continuity across the terminals once the inducer motor reaches full speed

offering the same mounting footprint and technical specifications

Direct OEM Compatibility: Specifically engineered for Rheem

Lennox 15D57 Defrost Board R-410A Built for non-reversing operationThe Lennox 15D57 Defrost Board is a high performance OEM defrost control kit specifically engineered for direct replacement in Lennox heat pump systems. As a veteran grade HVAC replacement part, this kit integrates a demand defrost control logic that actively monitors outdoor coil temperatures via the included 28W71 ambient sensor harness. This prevents excessive frost accumulation and optimizes system efficiency during low ambient operation. The