The Windhager BioWIN 350XL Automatic Boiler is a self-modulating pellet boiler that features state-of-the-art electronics designed to keep the boiler going only when it needs to, saving you a ton of energy and hassle in the process. Capable of up to 119,000 BTUs of heat and offering automatic pellet feeding, the 350XL is a robust solution to any home heating need and with a sturdy, high-quality build courtesy of Windhager, the 350XL is designed to last for many, many years.