Naturally, you would expect a heating contractor to recommend an annual furnace cleaning as we do. But we do so for a number of reasons. A cleaning means that your furnace will operate more efficiently, getting more heat for your fuel dollar. More importantly, however, the cleaning also includes a thorough safety check of the entire unit for cracked or defective/damaged parts. This annual maintenance check will assure you a carbon monoxide free winter. An annual cleaning is also recommended by all manufacturers as well as utilities. (ie. Union Gas).