(1) Except in the case of combination cylinders, every hot-water cylinder shall be provided with an expansion pipe discharging direct to the atmosphere in a position where overflow will be readily detected or, alternatively, discharging above the surface-level of the water in the storage tank supplying such hot-water cylinder.

(2) The supply pipe from any separate storage tank to a hot-water apparatus shall be fitted with an easily accessible gate-valve.

(3) Every water-heater shall be so constructed that the heating-unit or units shall remain covered by water under all normal conditions of use and under a temporary failure of water-supply.