A GeoCool ground source heat pump installation has been operating since February 2005, and it has been completely monitored since then. The performance analysis of the system during its first years of operation was presented in previous publications. This paper presents a detailed description of the analysis tool used, together with the results and analysis for thermal loads, performance factors, and load ratios over five years. It also provides a complete reference data set (water temperatures, flow rates, and power consumption) which can be used by researchers for model validation of this kind of installations. An example of software validation with experimental data is presented. (C) 2014 Elsevier Ltd. All rights reserved.