In this paper, thermo-hydraulic behavior of a solar heater is numerically investigated and optimum geometry for the angled-rib turbulator which produces the maximum thermal enhancement factor is determined by Taguchi method. A general innovative geometry is introduced for the rib, that changing in its geometrical parameters will lead to three convenient types of turbulators, namely triangular, rectangular and trapezoidal ribs, simultaneously. َApplying Taguchi method leads to the optimum geometry parameters. A L16 (44) orthogonal Taguchi array is used. The aim of the Taguchi analysis is maximizing the thermal enhancement factor. The factors employed for the analysis are rib relative pitch, height, tip width and percentage of upstream-side perpendicularity. The analysis has been carried out for a flow of Re=10000 and a constant rib width. Due to the twofold effect of turbulators on thermo-hydraulic behavior, thermal enhancement factor concept is employed which stands for both heat transfer rate and friction factor. Results show that rib pitch and height have the most effect on thermal enhancement factor, respectively. The optimum rib geometry is found to be a triangular rib which has P/H=2, e/H=0.2 and 100% perpendicularity.