Coolant heating device for vehicle

A coolant heating device for a vehicle, comprising:

• a housing having an inlet through which coolant is introduced, an outlet through which the coolant is discharged, and an internal space in which the coolant is heated;
• a heating unit disposed inside the housing, having an inner circumferential surface and an outer circumferential surface, and having electrode terminals on the outer circumferential surface and heat-generating patterns connected to the electrode terminals and configured to receive power, the heat-generating patterns configured to heat the coolant flowing along the inner and outer circumferential surfaces;
• and
• a support unit having one side joined to the outer circumferential surface of the heating unit to fixedly support the heating unit inside the housing,
• wherein the support unit includes a plate configured to partition an internal space of the housing, and
• the plate includes:
• a protruding portion protruding perpendicularly from one surface on an inner side of the plate and having a groove shape;
• and
• a connection hole formed in a bottom region of the protruding portion.