Sears Home Services and Home Depot both offer diagnosis and repairs for gas furnaces, as of 2015. Both services charge a fee for the diagnosis of the gas furnace though the fee varies based on location.
The heating repair services from Sears Home Services are rated with 4.6 stars out of 5 stars. The repair technicians primarily work on brands such as Carrier and Kenmore, but can work on most other brands, too. Home Depot offers similar services to their customers, and they can diagnose and repair most major brands. Before scheduling an appointment for a repair, customers are advised to ensure the company can repair the furnace brand in the home.