Subclass 1/30: Water heaters having heat generating means, e.g. boiler, flow-heater, water-storage heater (F24H 7/00, F24H 8/00 take precedence; details F24H 9/00; steam boilers F22B; domestic stoves or ranges with additional provisions for heating water F24B 9/00, F24C 13/00) Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating (F24H 1/5 takes precedence) with water mantle surrounding the combustion chamber or chambers (F24H 1/4, F24H 1/44 take precedence) the water mantle being built-up from sections