I heat with oil. Should this chimney be cleaned?  

1. Without a doubt! Oil fuel is considered and treated as solid fuel. Fuel deposits will accumulate in the flue pipe as well as the chimney. They should be swept at least once a year sometimes more frequently depending on the furnace operation. The furnace itself also should be cleaned by a certified oil mechanic.
    
2. Oil furnace chimneys should be treated the same as wood burning appliances.
    
3. Birds and animals love chimneys and the chimney can become non functional from bird nests or other debris blocking the flue.
    
4. Improperly tuned oil burners can produce a large quantity of soot in venting systems. These can ignite in some circumstances and produce a chimney fire with enough intensity to damage the chimney, home or residences.