Dryer Not Heating? Testing Thermal Fuses, Elements & Igniters

Electric vs. Gas Dryers: Two Different Heating Systems

The troubleshooting path depends entirely on whether your dryer is powered by 240V electricity or natural gas:

1. Burned-Out Electric Heating Element (Electric Dryers)

In an electric dryer, air is drawn across an open coil of coiled nickel-chromium resistance wire housed inside a metal duct chamber. When energized with 240 volts, this coil glows cherry red, heating the incoming air.

Over thousands of heating cycles, the wire becomes brittle. If lint restricts exhaust airflow, the element overheats, causing the wire to melt and snap. Once the wire snaps, the electrical circuit is broken and the dryer will blow room-temperature air indefinitely.

2. Tripped Thermal Fuse (The #1 Culprit)

The thermal fuse is a non-resettable safety device mounted directly on the blower housing or exhaust duct. It is calibrated to permanently blow if internal exhaust temperatures exceed safe operating limits (typically 196°F to 220°F).

Key Diagnostic Rule: A thermal fuse never blows without a reason! The underlying root cause is almost always a clogged lint trap or an exhaust vent duct blocked with lint. If you replace the thermal fuse without cleaning the vent pipe, the new fuse will blow within 24 hours. Read our companion guide on dryer airflow blockages and vent hazards.

3. Defective Gas Igniter & Solenoid Coils (Gas Dryers)

Gas dryers utilize a ceramic silicon carbide glow bar (igniter) to ignite natural gas:

1. The igniter receives power and glows intensely white-hot for 15 to 30 seconds.
2. A radiant flame sensor detects the heat and signals the gas valve solenoid coils to open.
3. Natural gas flows across the igniter, lighting the burner tube with a robust blue flame.

If the igniter is cracked, it will never glow. If it glows but clicks off without lighting, the solenoid coils have failed. These coils must then be replaced.

4. Faulty High-Limit or Cycling Thermostat

The cycling thermostat regulates drum temperature, cycling the heat source on and off to maintain chosen fabric settings (Low, Medium, High). If its internal bimetal contacts become stuck open, it will prevent current from ever reaching the element.

To book an appointment or view our flat-rate pricing structure, visit our main Santa Clara dryer repair service page.