The price varies from $100 to $200 depending on the furnace's fuel type, the cost of an inspection, the level of cleaning necessary, whether a filter change is necessary, and the labor costs associated with maintaining the furnace. If furnace repairs are necessary or if the homeowner decides to have their air ducts cleaned, the cost may go up. The cost may be covered by a home warranty, or the homeowner may decide to buy an annual maintenance plan from a reputable HVAC business.