How to Fix / Troubleshooting

Safety first: Ensure the oven is cool before touching any internal parts.

Improve ventilation: Check that the oven is not tightly enclosed without the recommended clearances. Remove any items stored on top of or directly against the oven.
Clean fan and vents: Access the cooling fan and gently clean dust and grease from the blades and surrounding vents.
Check fan speed: If the fan runs slowly or noisily, the motor may be weak and should be replaced.
Monitor operation: After cleaning and improving airflow, run the oven and observe whether H02 still appears.

Hitachi oven displays H02 and fan continues running for a long time after use

Possible Causes