Heating device

The device has a plate stack (30) that is formed of a fluid passage in a fluid-tight manner between a pair of plate (5,6). An electric heater element is sealed in the plates, and electrically isolated from the inlet side and the outlet-side fluid ports (11,12) of the fluid passage in the plate . The electric heater element comprises a connecting device (32) for electrical contact, which is connected to the electric heating element and projected through a window (31) between the plates. A fluid connector and the windows are located adjacent to opposite side edges of the plates.