Solar collector is a device that serves to collect the incoming solar energy and convert it into energy which in turn forwarded to the working fluid. A great systemof solar collector is a solar collector which has high efficiency, this means, most of heat energy that absorbed the collector can be used to water heater that flows inside and a small portion of heat energy is lost to the environment. In this study, the model of solar collectors has been modeled and heat transfer process to the solar collector solved by using software Engineering Equation Solver (EES). Iteration method is used to determine surface temperature in order to get useful heat energy on the collector. The solar collector simulated is measuring 1m x 2m x 0,06m, assumed absorber plate is aluminum and zinc plate size 0.4 mm and 0,6mm. The simulation results obtained fluid out temperature by using aluminum as the absorber is much higher than using zinc plate as the absorber plate. The fluid out temperature using aluminum plates as an absorber measuring 0.4 mm is higher than the plate size of 0.6 mm. The temperature of out fluid by using a copper pipe is larger than using a metal pipe for flat plate collectors for copper pipe that has higher thermal conductivity than the steel pipe. The simulation results are compared with the results of testing and the fluid out temperature of the test results is obtained less than the simulation results using the collector pipes and absorber plate of the same.