Yeah, but it uses electrical energy to mechanically turn a compressor. The compression and expansion of the refrigerant is what allows it to transfer heat from inside the house to outside, or by reversing the valve, heat from outside to inside. This is same physics that fridges, freezers and AC's use. A heatpump just allows the direction to reverse based on the needs.

It's a mechanical input that allows this to happen, not a heat input. So the heat from the miners won't drive a compressor. You need to turn that 'waste' heat from the miners into mechanical energy, but I think the stack of systems required to transfer the energy would induce more losses than the return could justify.

I'm just a clever amature, trying to use first principles, maybe a real physicis or engineer could explain it.