Abstract: A water heater appliance or heat transfer assembly may include a refrigeration system, an electronics board, and a heat pipe. The refrigeration system may include a sealed refrigerant loop. The electronics board may be attached to a housing. The heat pipe may extend between a conductive interface or electronics board and the sealed refrigerant loop to convey waste heat from the electronics board to the sealed refrigerant loop.

Abstract: A water heater comprises a tank, a cylinder coil section and a return-flow coil section. The cylinder coil section is in a heat transfer relationship with the tank and encircles a first portion of the tank. The return-flow coil section is in a heat transfer relationship with the tank and encircles a second portion of the tank. The cylinder coil section and the return-flow coil section are continuous over at least the first and second portions of the tank.