In this study, thermal performance of a 5 ton ground source heat pump system has been analyzed in heating mode of operation. Ground source heat pump system (GSHP) consists of a commercially available heat pump coupled with 5 double U- tube and one single tube borehole heat exchangers. All the boreholes are of 120 m depth except one borehole heat exchanger (BHE) which is 103 m depth (BHE I). Main focus of the present research work is to analyze the heat extraction behavior of the BHE from the ground and recovery period of the soil terrain when the set point temperature of the room is varied assuming as if heating load of the room is changing. For that purpose, temperature of the room is varied from a comfortable temperature (22°C) to 27 °C. During this process, it is observed that the rate of heat extraction from the ground decreases as the duration of experiment increases. The soil recovery period is found as 12 hours after operating the system for 6 hours. Although in normal condition when set point temperature of the room is 22 °C, and system operates for 6 hours for this the soil recovery period is estimated as 6 hours.