Your iron has switched into Celsius mode, and can be switched back to Fahrenheit mode easily by following the directions below: - Unplug the iron, then plug it back in, but do not turn it on. - Hold down on the increase temperature button, then at the same time, hold down the power button. - The iron's digital display should flash an 'F' and begin heating to its desired Fahrenheit temperature. Please note, this is not a reset for any other issue, and only works to switch the iron back into Fahrenheit mode. If the iron displays any other message than the 'F' or does not heat up to its maximum temperature, please contact our Customer Service Department.