Heater appliance, in particular electric storage water heater, comprising an electrical connection system between one or more resistances (R, R2, R3, Rn-th) and a thermostat of the heater appliance, said one or more resistances (R, R2, R3, Rn-th) being of the "candle"-type from the two ends (MR', MR) whereof two pins protrude, said one or more resistances (R, R2, R3, Rn-th) being constituted by a resistive filament contained in a metal tube armor bent on itself to form two parallel branches, wherein the first one of said one or more resistances (R, R2, R3, Rn-th) comprises a pair of connectors (1; B) constrained to said two pins, said pair of connectors (1; B) comprising female fastons (1.CR) located in a position in axis with male fastons of said thermostat, for the purpose of axial insertion for the reciprocal coupling, characterised in that each of said pair of connectors comprises: - a first arm (1.1) developing orthogonally outwards with respect to the longitudinal axis of said resistance, said first arm (1.1) having: - the proximal end (1.10) adapted to be constrained to one of said two pins, - the distal end (1.11) connected to a second arm (1.2), - said second arm (1.2) developing substantially orthogonally with respect to said first arm (1.1) and having the distal end (1.20) connected to one of said female fastons (1.CR), - said female faston (1.CR) being directed downwards, orthogonally to said second arm (1.2). said one or more resistances (R, R2, R3, Rn-th) being of the "candle"-type from the two ends (MR', MR) whereof two pins protrude, said one or more resistances (R, R2, R3, Rn-th) being constituted by a resistive filament contained in a metal tube armor bent on itself to form two parallel branches, wherein the first one of said one or more resistances (R, R2, R3, Rn-th) comprises a pair of connectors (1; B) constrained to said two pins, said pair of connectors (1; B) comprising female fastons (1.CR) located in a position in axis with male fastons of said thermostat, for the purpose of axial insertion for the reciprocal coupling, characterised in that each of said pair of connectors comprises: - a first arm (1.1) developing orthogonally outwards with respect to the longitudinal axis of said resistance, said first arm (1.1) having: - the proximal end (1.10) adapted to be constrained to one of said two pins, - the distal end (1.11) connected to a second arm (1.2), - said second arm (1.2) developing substantially orthogonally with respect to said first arm (1.1) and having the distal end (1.20) connected to one of said female fastons (1.CR), - said female faston (1.CR) being directed downwards, orthogonally to said second arm (1.2). - a first arm (1.1) developing orthogonally outwards with respect to the longitudinal axis of said resistance, said first arm (1.1) having: - the proximal end (1.10) adapted to be constrained to one of said two pins, - the distal end (1.11) connected to a second arm (1.2), - the proximal end (1.10) adapted to be constrained to one of said two pins, - the distal end (1.11) connected to a second arm (1.2), - said second arm (1.2) developing substantially orthogonally with respect to said first arm (1.1) and having the distal end (1.20) connected to one of said female fastons (1.CR), - said female faston (1.CR) being directed downwards, orthogonally to said second arm (1.2).