Power generation through photovoltaic thermal (PVT) systems is an effective technology to solve the global energy scarcity problem. Therefore, reliability and maintenance of PVT systems is of utmost importance as it ensures the proper functioning of these systems. The various benefits of using photovoltaic thermal systems includes generation of electrical power, thermal energy, increased system efficiency and reduction in CO2 emissions. This work aims to review the reliability and maintenance analysis of works done by various researchers. It has been observed that the evaluation of reliability and maintenance of renewable energy systems is a significant means to achieve environment Sustainability. The reliability of solar photo voltaic thermal (PVT) systems are calculated on various environmental conditions like high temperature, UV radiation, outdoor exposure etc. And different methods like fault tree analysis, finite element method and probabilistic technique are utilized for the computation of system reliability.