A heating device includes a heater to heat an object to be heated, a temperature detector to detect a surface temperature of the heater, a power calculator to calculate a power consumption of the heater, an abnormality detector to detect an abnormality of the temperature detector, and circuitry to cause the heater to increase the surface temperature of the heater from a first temperature to a second temperature higher than the first temperature; cause the power calculator to calculate the power consumption of the heater increased to the second temperature; cause the abnormality detector to compare the power consumption calculated by the power calculator and a predetermined threshold value; and cause the abnormality detector to determine that the temperature detector is abnormal when the power consumption calculated by the power calculator is equal to or larger than the predetermined threshold value.