Abstract :
Boiler is the main component in a steam power plant which serves to produce steam with a specific temperature and pressure from the process of boiling water. Steam power plant in PT IndoLampung Perkasa using bagasse as the main fuel. Although using different fuels such as in general (i.e. coal), a component of the boiler on PT IndoLampung Perkasa?s steam power plant remains the same as boilers in general. To keep the performance or efficiency of boilers, overhaul needs to be done. Efficiency is one of the many parameters that are used to assess whether or not the performance of a boiler. Overhaul on PT IndoLampung Perkasa? steam power plant done when the milled sesion end. However, after a complete overhaul, has never done the calculations for the efficiency of the boiler. Therefore, in this thesis will be calculated the value of boiler efficiency after the overhaul. In calculating the efficiency of boilers, used the formula according to Japanese Industrial Standard (JIS) B 8222-1973, with heat lose method. The initial boiler efficiency was 75.12 %, and currently boiler efficiency is 74.22 %. Boiler efficiency decline is 0.9 %