Hot oil heater is used for the purpose of heating bitumen in the existing bitumen heating systems in asphalt factories. This machine transfers the heat towards the bitumen flask and two-shell pipes located in the asphalt factory by circulating hot oil in the system. The sample of this machine is inspired by the Italian Marini design and has been manufactured with 250,000 to 1200,000 kilocalories thermal capacities and is equipped with conditioner, pressure control automatic control systems, oven’s temperature level automatic control, thermal oil automatic air bleed, and thermal oil level automatic control system on customer’s demand. The machine has an only maintenance instruction which is submitted to the customer for use, service, maintenance and repair inspections and guarantee or warranty conditions. The guarantee and warranty periods are 6 and 120 months, in respect.