Microwave stops mid-cycle and displays E04; sometimes accompanied by a hot cabinet or fan running on after cycle.

Safety: Unplug the microwave and allow it to cool completely before inspection.

Steps:

• 1. Check ventilation: Ensure that built-in IKEA microwave/oven combos are installed with the correct trim kit and clearances. Remove any items blocking the front or rear vents.
• 2. Clean filters and vents: For integrated models, remove grease filters and clean them with warm soapy water. Vacuum dust from intake and exhaust vents.
• 3. Let the unit cool: Leave the door open and allow the microwave to cool for 30–60 minutes, then try a short heating cycle. If E04 returns quickly, the sensor or fan may be faulty.
• 4. Inspect cooling fan (for competent DIYers): Remove the outer cover and check that the cavity cooling fan spins freely and is not obstructed. Spin the blades by hand; they should move smoothly.
• 5. Test temperature sensor: Locate the cavity NTC sensor (usually on the top or side of the cavity). Check its resistance at room temperature and compare with service data. A sensor that is open or shorted must be replaced.

Resolution: Clear ventilation issues first. If the fan and vents are fine, replace the cavity temperature sensor or thermal cut-out with the correct IKEA/Whirlpool/Electrolux-compatible part.