An icemaker assembly includes a mold body defining a plurality of cavities. A working fluid line is directly attached to the mold body, and a drain duct is disposed below the mold body. A defrost heating element is positioned below the mold body and within the drain duct. The defrost heating element is spaced from the mold body, and the defrost heating element is operable to melt frost on the mold body with radiant heat from the defrost heating element. A related appliance is also provided.