A dry-type transformer heater includes a closed housing, and at least one transformer winding arranged in the housing. The at least one transformer winding includes at least one corresponding winding conductor and a corresponding insulation layer surrounding the transformer winding, respectively. In addition to the respective winding conductor, at least one coil heating wire is provided in at least one of the insulation layer and on the surface of the insulation layer to input thermal power into the respective insulation layer.