Lennox 15D57 Defrost Board Els PW 29614 and D7CG rooftop units and

and D7CG rooftop units and furnace assemblies

Carbon buildup (soot) on the flame rod or a cracked ceramic insulator are common failure points

and SC ranges

What is the difference between MKC-1 and MKC-2 coils

The C501-7 utilizes ODF (Open Die Forging) sweat connections

Lennox 15D57 Defrost Board Els PW 29614 and D7CG rooftop units andThe 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