Why does a solid fuel aga cooker sometimes smoke through the refuelling plug?

A solid fuel Aga cooker may smoke through the refuelling plug due to incomplete combustion or insufficient airflow, which can cause smoke to back up when the fire is disturbed during refueling. If the flue is blocked or the chimney has poor draft, this can exacerbate the issue. Additionally, using damp or low-quality fuel can lead to increased smoke production. Ensuring proper fuel and regular maintenance can help minimize this problem.