Patent ID: 6897416

Claim:
An electrical heater for the heating of air, comprising: a fan for generating an air current, at least one PTC element for heating the air current and a control device for setting the effective air throughput from the fan and for setting the generated heat output from one of the PTC elements, wherein the control device is configured such as to exclude the setting of the air throughput and the heat output below specified lower boundaries (P min , V min ), and wherein the electrical heater contains, a measurement device configured to determine the power consumed by the PTC element, a comparison device configured to compare the power measured by the measurement device with a specified power threshold value (Plim), which is smaller than the lower boundary of the adjustable heat output (Pmin), and a detection device configured to recognize an interruption of the air current from the fan when the comparison device determines that the measured power consumed by the PTC element drops below the specified power threshold value (Plim).