This paper investigated the use of fatty acid distillate (FAD) produced as a by-product of edible oil refining as a fuel source for boilers. Using a diesel heater to model the combustion chamber of a fire tube boiler showed that diesel blends with FAD up to 60 could be used with different levels of preheating. A small to medium sized edible oil refinery was used to generate an economic model. It was estimated that an edible oil refinery of this size required a boiler able to supply 3 GJ/h of energy. In this situation, the FAD produced could provide approximately 57 of the yearly energy requirements for the boiler. An economic analysis revealed that using FAD (42 MJ/kg) as fuel will increase its value from New Zealand Dollar () 0.425/kg to approximately 1.30�1.55/kg depending on the cost of standard boiler fuel. Running the boiler on LPG (30/GJ) or diesel (37.7/GJ) was estimated to cost 960,000 and 1,200,000 respectively per year. If all the FAD was used as alternative fuel to provide 57 of the yearly energy, then up to 700,000 could be saved each year. © 2021 The Authors