Heat pump - Wikipedia A heat pump is a device that transfers heat energy from a source of heat to what is called a thermal reservoir.Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink. Related searches for engine diagram heat pump heat pump parts diagramheat pump electrical diagramheat pump wire diagramfire engine pump diagramheat pump thermostat wiring diagramheat pump control wiring diagramheat pump wiring diagram schematicgoodman wiring diagram heat pump