Heat exchangers are an indispensable part of many chemical processes. These are the systems that allow the transfer of heat between two or more fluids. The dynamics of heat exchangers are highly nonlinear; thus, many methods have been used to control these systems. Feedback, feedforward and cascade control loops can be presented as traditional methods. The type of controller used in these systems is also crucial, and controllers such as P, PI, PID are widely used in industry. Because of the complexity of the control, intelligent controllers like fuzzy logic controllers (FLCs) are also considered to provide an alternative to existing controllers, since FLCs provide ability to implement human knowledge and experience. In this study, control of a heat exchanger with process gain Kp = 50 and process time constant τ = 30 was investigated by using a fuzzy controller with feedback control loop. By comparing the conventional membership function for the fuzzy variables with proposed membership function, the response of the heat exchanger system to a step change of 10 units applied to the setpoint was interpreted.