Lennox 15D55 Control Board

The Lennox 15D55 Defrost Control Board is a critical OEM replacement component engineered to manage the complex defrost cycles of Lennox heat pump systems. As a veteran technician knows, maintaining the integrity of the outdoor coil is paramount; this board utilizes advanced demand defrost logic to monitor coil and ambient sensors, preventing efficiency-robbing frost buildup. With high-temp ratings up to 105°C and a robust 47µF capacitance, the Lennox 620244-01 is built to withstand the rigors of continuous outdoor operation. This defrost controller features an integrated 5-strike lockout circuit for pressure switch monitoring and a selectable 30-second compressor delay to protect the scroll during cycle transitions. Whether you are troubleshooting fault codes on an EL16XP1 or performing a preventative board swap, this genuine HVAC circuit board ensures precise timing and reliable system recovery in demanding climates. Its terminal strip layout allows for straightforward field connections with existing wiring harnesses, minimizing diagnostic time and labor costs during emergency service calls.

• Demand Defrost Technology: Optimizes cycle frequency based on actual frost accumulation rather than simple timers, increasing overall SEER efficiency.
• Integrated System Protection: Features a built-in anti-short cycle timed-off control to protect compressor windings from rapid restarts.
• Diagnostics Support: Utilizes onboard LED sequences to indicate pressure switch lockouts and internal hardware failures for faster field troubleshooting.
• Versatile Compatibility: Direct replacement for multiple Lennox heat pump controls and catalog numbers, including 620244-01 and 100135-07.
• Field Configuration: Includes a factory-installed jumper for selectable delay and a dedicated manufacturing test mode for verifying operation during commissioning.

• What are the symptoms of a failed Lennox 15D55 board? A malfunctioning board typically results in the outdoor fan motor failing to stop during defrost, excessive ice buildup on the coil, or the unit being locked out on a high/low pressure code indicated by the status LEDs.
• Can I use this board for 2-stage Lennox heat pumps? This specific control is designed for select Lennox HVAC models; always verify the pin configuration and terminal markings on your existing Lennox 15D55 to ensure all staging signals and sensor inputs align.
• Does this board handle the compressor delay? Yes, the 15D55 Control Board has a selectable feature to cycle the compressor off for 30 seconds at the start and end of the defrost cycle to equalize pressure and manage noise.

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.