The aim of the present work was to experimentally investigate the combustion properties of methyl-ester of rapeseed oil (RME) that was preheated for three distinct temperatures ((30, 70, 110)degrees C) in the study. The experiments were carried out in a water-cooled horizontal combustion chamber with a nominal thermal load of 1500 kW. The experimental results were compared to the results obtained from the combustion tests with extra light heating oil (ELHO) that was used as a comparative fuel. The fuel was atomized by means of the twin-fluid effervescent atomizer with a maximal output of 100 kg h(-1) of oil at gas to liquid mass flow rate ratio (GLR) equals to 20%. Primarily the experiments were focused on the investigation of the flame characteristics and the quality of combustion at distinct heat outputs ((475, 700, 900) kW) and distinct GLR ratios ((10, 15, 20)%). Second, experiments focused on the evaluation and comparison of local wall heat fluxes along the flame length and were performed only for one setting of operating conditions, namely for the heat output of 900 kW and the GLR 15%. The results revealed that substitution of ELHO requires preheating of RME to the temperature of about 70 degrees C, if pneumatic atomization is to be used. The preheating of RME to higher temperature did not show any significant improvement in terms of quality of combustion. Moreover, it causes the increase in nitrogen oxides formation up to 60% in comparison with the values measured during ELHO combustion. (C) 2012 Elsevier Ltd. All rights reserved.