Can a geothermal heat pump also heat water?

Yes. Using what’s called a desuperheater, some types of geothermal heat pumps can save you up to 50 percent on your water-heating bill by preheating tank water. Desuperheaters are standard on some units, optional on others. Some geothermal models can provide all of your hot water needs on demand at the same high efficiencies as the heating/cooling cycles.