A brand new range of light commercial gas fired, high efficiency wall hung condensing boilers with individual outputs from 10kW to 145kW. Utilising a new state-of-the-art double helix finned tube stainless steel heat exchanger design; the boilers have a high turndown rate of 1:6, affording the potential for accurate output-to-load matching. THISION L is the product of extensive research, development and field testing. THISION L wall mounted boilers set new standards in gas fired condensing boiler reliability, performance and design features.