F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
F24H1/22—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating
F24H1/24—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water mantle surrounding the combustion chamber or chambers
F24H1/30—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water mantle surrounding the combustion chamber or chambers the water mantle being built up from sections
F24H1/32—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water mantle surrounding the combustion chamber or chambers the water mantle being built up from sections with vertical sections arranged side by side