Bio-Tec L wood boilers, with a heat output of 25, 32 and 45 kW are powered by wood with moisture lower than 25%. Through the pyrolysis principle, the fuel is completely burned. The large fireplace allows the boiler to be powered with pieces of wood up to 550 mm long. A load of wood lasts at least 5 hours and can be increased throughout the day by working at lower temperatures. The boiler can maintain the embers for up to 12 hours and boiler management is controlled by the lambda sensor, installed as a standard device, which acts by automatically adjusting the actuators of the primary and secondary air registers and the speed of the smoke aspirator. The boiler is easy to manage and is equipped with a color display which guarantees easy use.