Yes, geothermal systems can be used to run radiators. Geothermal systems use the natural heat from the ground to heat a home, and this heat can be used to run radiators. The geothermal system works by circulating a fluid through a loop of pipes buried in the ground. The fluid absorbs the heat from the ground and carries it back to the home, where it is used to heat the radiators. The system is highly efficient and can provide a reliable source of heat for radiators.