FLOW HEATER

Disclosed is a flow heater, comprising a housing comprising a base part (1) and a cover part (2), a channel for liquid to be heated, which extends from an inlet (4) to an outlet (5), a heating plate (8) adjacent to the channel, fins (20) arranged in the channel in contact with the heating plate (8), and a printed circuit board (16) arranged between an inner wall (9) of the housing and the cover part (2). According to the invention the inner wall (9) has at least one section that is slanted with respect to the heating plate (8), between the heating plate (8) and the inner wall (9) the channel has a first wedge-shaped section (7) downstream of the inlet and a second wedge-shaped section (6) leading to the outlet (5), both wedge-shaped sections tapering from an end of the heating plate (8) adjacent to the inlet (4) and the outlet (5) to an opposite end, wherein said wedge-shaped sections (6, 7) are connected by a middle section of the flow channel, in which the direction of flow is crosswise to the direction of flow in the wedge-shaped sections (6, 7), the printed circuit board (16) is slanted with respect to the heating plate (8), and the printed circuit board (16) is slanted with respect to the cover part (2) and arranged in a wedge-shaped space defined by the inner wall (9) and the cover part (2), said wedge-shaped space tapering in a direction that is opposite to the direction in which the first and second wedge-shaped channel sections (6, 7) taper.