The thermal fuse is a safety device designed to protect the dryer from overheating. The fuse is located on the blower housing or at the dryer’s heat source such as the heating element on electric dryers or at the burner on gas models. The fuse should be closed for continuity meaning it has a continuous electrical path through it when good. If overheated the fuse will have no continuity meaning the electrical path is broken and the fuse has blown. A multimeter can be used to test it for continuity. Be aware that a blown thermal fuse is an indication of a restricted exhaust vent from the dryer to the outside. Always check the dryer venting when replacing a blown thermal fuse.
Gas Valve Solenoid
Gas dryers have two or more gas valve solenoid coils. The gas valve solenoids open the gas valve ports to allow gas to flow into the burner assembly. If a gas valve solenoid fails, the dryer won’t heat. To determine if one or more of the gas valve solenoids has failed, check the igniter. If the igniter glows and goes out but does not ignite the gas, the gas valve solenoid is defective. If one or more of the gas valve coils are defective, I recommend that you replace them as a set.