An apparatus for managing water levels in a boiler, in particular a boiler of a coffee machine, in which the boiler (12) comprises, connected to a control circuit (14): a first probe (21) arranged, in use, to measure a first water level; at least a second probe (22, 23) arranged to measure a second level, or working level of the apparatus, higher than the first level, in which it is provided that the apparatus is arranged to supply steam or hot water through respective ducts (26, 27) connected to the boiler (12) and controlled by respective valves (36, 37). The first probe (21) is configured for measuring a draining level of the boiler on the basis of draining commands generated by the control circuit and for automatically enabling water replacement in the boiler.