A fusing unit and an image forming apparatus including the same, and method are provided. The fusing unit senses an error such as local overheating in a surface heater, which uniformly emits heat throughout the surface of a belt member. The fusing unit includes a heating member with a pattern to heat a recording medium, a power supply to supply power to the heating member, a pressing member to transmit rotational force to the heating member while in contact with the heating member and to apply pressure to the recording medium, a driver to rotatably drive the pressing member, a pattern sensor to sense the pattern, and a controller to determine whether there is an error in the rotation of the heating member, based on an output from the pattern sensor.