Two hydrogeological numerical models (2D and 3D) for the geothermal area located to the West of the Nevado del Ruiz volcanic complex (Colombia) are presented here. They are built with the software HydroGeoSphere using data collected in the field, as well as hydraulic and thermal properties measured on rock samples in previous laboratory studies. The purpose of this modeling work is to analyze the influence of faults aperture and depth on groundwater flow circulation and heat transfer in the geothermal reservoir. The 2D model illustrates the relation between fault aperture and temperature distribution. The 3D model shows the behavior of a potential production well located in the Botero-Londoño area that withdraws hot water from a depth of 2600 m. The results highlight the usefulness and limitations of this approach, providing guidelines for future numerical models of this site and for the initial modeling work for any fractured geothermal reservoir. © 2025, Universidad Nacional de Colombia. All rights reserved.