In this paper, the effect of weather conditions on profit of a two unit cold standby system under preventive maintenance and repair has been examined. The units are identical in nature which may fail directly from normal mode. There is a single server who visits the system immediately whenever required and works only in normal weather conditions. The operative unit under goes for preventive maintenance after a specific time of operation. Repair of the unit is done by the server at its complete failure. The repair activities are perfect. The time to failure of the unit follows negative exponential distribution while the distributions of preventive maintenance and repair times are taken as arbitrary with different probability density functions. All random variables are statistically independent. The expressions for several reliability measures are derived in steady state using regenerative point technique and semi-Markov process. The graphical behavior of MTSF, availability and profit function have been observed with respect to preventive maintenance rate for arbitrary values of other parameters and costs.