Regards. What model is the dryer? This fault appears in many dryers, when fibers in the heat outlet duct accumulate, fiber particles that shed the clothes or when the thermistor found in this duct is defective. Suggestions: - Verify that there is no excessive accumulation of dust / lint in the pipeline. - Check the thermistor. The value can be between 40 and 50 KOhm for some models, but to do it with precision, better look for information on the model of your dryer.