The B5 water heater is especially designed for little space. They consist of an integrated heat exchanger, a small combustion chamber and have a heating power of 6kW. It has a constant water share of about 46%.The B4 water heater can provide up to 9kW and have a modern cleaning system, which can be ordered with it. It consists of a set of cleaning springs with an actuating lever. The water boiler power is constant between 45 to 55% regarding combustion heat.