RCA oven emits a buzzing or humming noise from the control area when heating.

Safety first: Disconnect power at the breaker before accessing the control area.

• Localize noise: Run the oven and carefully listen to identify whether the noise comes from the fan, control board, or elsewhere (do this before disconnecting power).
• Inspect fan: If the cooling fan is noisy, check for debris in the blades and ensure the cooling fan motor is securely mounted. Replace if bearings are worn.
• Tighten hardware: With power OFF, tighten all screws securing the control board, transformer, and metal brackets.
• Control board: If a relay is chattering or buzzing excessively, the electronic oven control board may be failing and require replacement.