The efficient energy policies and its inherent practices are promoting new operating modes of the transformers. Independently of the practices, the temperature remains one of the most relevant limiting factors, being thus essential to predict accurately its distribution and magnitude. Addressing this specific challenge, the thermal hydraulic network models (THNMs) are enhancing our comprehension, by revealing fluid velocities and temperatures inside transformer windings with immense detail. The aim of this work is the assessment of the steady state performance of a proprietary THNM — named FluCORE — by comparing its outputs with different measurements collected from two real core type power transformers. In the absence of direct oil flow rate measurements inside the windings, alternative indirect methods to assess the oil flow distribution are also presented. At the end, it is observable that while the temperature magnitudes can be predicted with reasonable accuracy, the hot-spot location in real transformers by calculation and its measurement is still a matter of complex research.