Microwave displays E5 and may shut down during long cook cycles or convection use.

Safety: Unplug the microwave and allow it to cool completely before servicing. High temperatures can cause burns.

• Check ventilation: Ensure all vents on the Viking microwave are clear and that the unit has proper clearance from cabinets and walls.
• Allow cooling: Leave the door open and wait at least 30–60 minutes, then try operating again. If E5 clears temporarily, overheating is confirmed.
• Inspect cooling fan: Remove the outer cabinet and verify that the internal cooling fan runs when the unit is started. Replace the Viking cooling fan motor if it is not operating or is noisy/seized.
• Check thermal cutouts: Locate the thermal cutouts (thermostats) on the magnetron and cavity. Inspect for discoloration or loose mounting.
• Replace faulty thermal cutout: If a thermal cutout has failed open (testing with a meter recommended for professionals), replace it with the exact Viking-rated part.