Its size means that it can be installed neatly into your standard kitchen cupboard, out of sight, out of mind. However, it is important to note that when purchasing a new or replacement system boiler, you will need to accommodate for an additional hot water cylinder which is used to store the hot water that is heated from the mains. A system boiler allows for a high demand for hot water, whenever it's required.
The EcoTec Plus 637 is the most powerful of its range with an output of 37.6kW, best suited to large-sized homes with up to 20 radiators. If your home has less than 20 radiators, then the EcoTec 612, 615, 620, 625, and 630 are also available with outputs from 12kW to 30kW.