By using a ground source absorption heat pump (GSAHP) to transform the operation of a conventional heating system (CHS), the GSAHP can significantly increase the economics and energy efficiency of the system. Hot water from the heating pipe network drives the GSAHP and the GSAHP can then extract geothermal energy. When compared with the CHS, the new system can improve energy efficiency by 54% and reduce annual operating costs by nearly 30%. The new system using a GSAHP can replace a ground source electricity-driven heat pump system (GSEHP). The new system is more energy efficient than a GSEHP and should improve energy efficiency about 61% and, compared to a GSEHP system, should decrease the heating system's primary power consumption by about 38.2%. The new system also has the advantage of having a physically smaller underground heat exchanger. The system would extract less heat during winter months and this would result in better winter and summer heat balance. Using a GSAHP, energy cascade utilization would be achieved.