Wood stoves and fires are consumer products that slowly but surely become dirty as a result of combustion. Components may also over time become subjected to wear and tear. This is why we strongly recommend you have your stove or fire serviced annually. Your dealer or installer can advise you, and can ultimately take care of maintenance for you.
In addition, it must be ensured that the air supply doesn't become blocked by ash, but this is easy enough for the user to do themselves. What the user often cannot do is clean the flue duct. Your chimney will require regular sweeping; the frequency will depend on the type of stoking and wood used.