A heater can move more heat than the energy it consumes

A heat pump often delivers two to four units of heat for one unit of electricity, because it is moving heat, not making it.

The same circuit as a refrigerator, run with the cold side outside and the warm side in the room. A compressor raises the temperature of a refrigerant enough that it can dump heat into the house, then lets it expand and become cold enough to pick up more heat from air that already felt cold to you. The electricity pays for the pumping. The heat itself was already there, outdoors, even on a day you would not call warm.

The multiplier has a name, the coefficient of performance, and it is not a constant. It shrinks as the gap between outside and inside grows. On a mild day a good pump looks like a small miracle. On a hard freeze it works harder and the miracle thins. It never becomes a violation of the second law, because the outdoor air, or the ground, ends up that little bit colder.