Water heater system, comprising a water heater, a wall mounting bracket having at least two hook receiving portions, at least two hooks coupled to the water heater configured to engage into the at least two hook receiving portions of the wall mounting bracket, wherein the hook receiving portions are arranged in the wall mounting bracket without a connection to a circumference of the wall mounting bracket, and the water heater system further comprising a fixation bracket coupled to a housing of the water heater, wherein the fixation bracket comprises at least two first through holes (221 - 226) arranged substantially in the middle of the fixation bracket, which are configured such that the fixation bracket is mounted to the water heater, and at least two second holes (231 - 236) configured for fixing the hooks to the fixation bracket to allow a vertical or horizontal mounting of the water heater, or an outer bracket configured to be attached to a round housing of the water heater, wherein the outer bracket comprises a first and second end (510, 520), a middle portion and two mounting portions, each between the middle portion and the first and second end (510, 520), wherein the at least two hook receiving portions are configured to allow a vertical or horizontal mounting of the water heater, wherein the at least two hooks are attached to the fixation bracket or to the outer bracket in a way that the at least two hooks engage into the at least two hook receiving portions in a first direction to allow a vertical mounting of the water heater, or wherein the at least two hooks are attached to the fixation bracket or to the outer bracket in a way that the at least two hooks engage into the at least two hook receiving portions in a second direction being perpendicular to the first direction to allow a horizontal mounting of the water heater. a water heater, a wall mounting bracket having at least two hook receiving portions, at least two hooks coupled to the water heater configured to engage into the at least two hook receiving portions of the wall mounting bracket, wherein the hook receiving portions are arranged in the wall mounting bracket without a connection to a circumference of the wall mounting bracket, and the water heater system further comprising a fixation bracket coupled to a housing of the water heater, wherein the fixation bracket comprises at least two first through holes (221 - 226) arranged substantially in the middle of the fixation bracket, which are configured such that the fixation bracket is mounted to the water heater, and at least two second holes (231 - 236) configured for fixing the hooks to the fixation bracket to allow a vertical or horizontal mounting of the water heater, or an outer bracket configured to be attached to a round housing of the water heater, wherein the outer bracket comprises a first and second end (510, 520), a middle portion and two mounting portions, each between the middle portion and the first and second end (510, 520), wherein the at least two hook receiving portions are configured to allow a vertical or horizontal mounting of the water heater, wherein the at least two hooks are attached to the fixation bracket or to the outer bracket in a way that the at least two hooks engage into the at least two hook receiving portions in a first direction to allow a vertical mounting of the water heater, or wherein the at least two hooks are attached to the fixation bracket or to the outer bracket in a way that the at least two hooks engage into the at least two hook receiving portions in a second direction being perpendicular to the first direction to allow a horizontal mounting of the water heater.