Dryer runs but does not heat, E04 displayed after a few minutes of operation

Safety first: Disconnect power before accessing the rear panel or heater assembly.

Step-by-step checks:

• Confirm no heat: Run the dryer on a high heat cycle for 5–10 minutes. Open the door and feel inside; if the air is room temperature and E04 appears, proceed with heater checks.
• Access heater assembly: Remove the rear panel. Locate the heater housing, high-limit thermostat, and thermal cutoff devices.
• Test heater element: Disconnect the heater terminals. Use a multimeter to check resistance across the element; a typical reading is between 8–20 ohms (varies by model). Infinite resistance indicates an open element that must be replaced.
• Check thermostats and cutoffs: Test each thermostat and cutoff for continuity at room temperature. Replace any open devices, but also inspect for restricted airflow that may have caused overheating.
• Control board relay: If all components test good, the heater relay on the main control board may not be closing. Listen for a click when the dryer calls for heat. If no click and voltage to the relay coil is present, the board is likely faulty and needs replacement.

When to call a technician: If you are not comfortable testing live voltage or replacing the control board, seek professional help.