Industrial Oil Heaters for Furnace are fitted with renewable cartridge type heating elements to replace the heating elements without draining the fuel tank. These Industrial Oil Heaters come with dual thermostat, one for operation and other for safety with indicating lamps. These Industrial Oil Heaters are provided with thermometer to monitor the temperature. These Industrial Oil Heaters for Furnace are also provided with Inlet/Outlet/Drain connection and a safety valve for higher capacity.