The rotating parts of oil burners can go out of balance as parts (motor and fan bearings, pump bearings) wear or get dirty. This can also be a coupling alignment problem. Thumping and rumbling at the burner may be a nozzle problem. Service people often replace the nozzle and cure the problem. Noisy operation may result from air in the inlet line.
There is no short-term implication of noisy burners, other than annoyance. However, vibration will accelerate the deterioration of the burner components.
Run the burner and note the noise. Oil burners should produce a fairly loud, steady drone. It is often possible to hear the oil burner noise throughout the entire house. Any uneven or high-pitched noises coming from the burner should be noted.
Place your hand on the top of the
. This is typically a black box roughly 5 inches by 4 inches by 4 inches tall. It's usually at the top of the burner. It converts house current at 120 volts to very high voltage, so a spark can be generated at the electrode. The burner unit should have a slight, steady vibration while running. Dramatic vibration is a cause for concern.