The 7 most common part(s) or condition(s) which cause the symptom Dryer doesn't heat are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 2986
If the dryer doesn't heat, but the drum turns, check the thermal fuse(s). The thermal fuse protects the dryer from overheating and helps to prevent fires. If the thermal fuse is blown, it will have to be replaced.
RepairClinic Item # 3479
The gas valve has two or more electric solenoids which open the valve to let the gas flow into the burner assembly. If the dryer doesn't heat one or more of the solenoids may be defective. If the igniter glows for 90 seconds but the burner flame doesn't light, replace these coils as a set.
RepairClinic Item # 3415
If the dryer doesn't heat, the igniter might be burned out. Check the igniter for continuity with an ohm meter. Dryer igniters burn out over time, similar to a light bulb.
RepairClinic Item # 2681
Gas dryers have a flame sensor to detect the heat given off by the flame. If the dryer doesn't heat, the flame sensor might be defective. Check the flame sensor for continuity. This is not as common as a burned out igniter or thermal fuse.
RepairClinic Item # 2311769
Although not common, if the dryer doesn't heat the high limit thermostat can be defective. It can be checked for continuity. If the thermostat is "open" the dryer doesn't heat.
RepairClinic Item # 2893
The cycling thermostat regulates the temperature of the air in the dryer. If the dryer doesn't heat it may be caused by a defective cycling thermostat. This is not common.
RepairClinic Item # 831500
The timer is normally not at fault if the dryer doesn't heat. In many situations where timers are replaced they end up being returned. Check all of the more common components in this troubleshooting guide before replacing the timer.