In this study, the performance of the helical coil heat exchanger is experimentally tested. The results are statistically analyzed using the response surface methodology (RSM) to optimize the heat exchanger response under various parameters. The helical coil outlet temperature is measured as the heat exchanger response. The considered parameters, affecting the performance, are the inlet temperature and pressure to the helical coil in addition to the water bath temperature surrounding the coil. Also, the mutual interactions between these parameters and their influences on the response of the helical coil are evaluated. This study is carried out in two parts, the first part is devoted to perform the experimental tests, and the second part deals statistically with the modelling and optimization of these results. Design of experiments (DOE) is provided according to the full factorial design method. Three parameters with three levels lead to performing 27 experimental runs. Finally, the results are modelled by the RSM method, and the adequacy of the model is verified by ANOVA analysis. The analysis of each parameter effect was performed to identify and rank various critical parameters relative to their order of importance. A complete RSM statistical model with a full factorial design is established. The results show that the statistical model equation has an accuracy of more than 98% to predict the output response of the heat exchanger. The inlet temperature has a dominant effect on the response by 30%. The mutual combination between the investigated parameters shows that the most important correlation is between the inlet temperature and pressure. The developed model enables the optimization of the outlet temperature response without referring to the physical and thermal properties of the used fluid.