Photovoltaic/Thermal (PV/T) systems are getting attention due to limitations in rooftop space, especially in apartment buildings. Those buildings must improve electricity generation from photovoltaic (PV) systems and hot water for domestic use. PV/T systems were investigated experimentally for Jordanian weather in this paper. Thermal and exergy efficiency was evaluated for commercially available PV/T panels under different connection configurations, open-loop, and closed-loop connections. Results showed a significant effect for the PV/T panel for Jordanian weather. Closed-loop performance can be improved if the heat collected by PV/T is extracted from the tank. Finally, the total efficiency of the PV/T system in an open-loop configuration is significantly higher, 76 %, than in a closed-loop one, 58 %, due to the improvement in thermal efficiency.