Founded as a boiler construction company in 1865, LOOS is able to look back on an eventful company history. The product development that was probably most important for the company's success was patented in 1952. The horizontal 3-pass flame tube/smoke tube boiler with internal, water-cooled flue gas reversing chamber was born. This boiler design, which certainly attracted attention in the 1950s, proved to be so sturdy, durable and universally usable that the product name "LOOS UNIVERSAL boiler" is still seen as a synonym of quality, even today.