• Shrill whistling noise


    I had the furnace cleaned last month to prepare for winter. Now I hear a shrill whistling sound from the furnace just before the blower kicks on. What causes this noise?

    Kathy, Greenwood, IN

    One possibility: If you have a humidifier on your system, it may be energizing and causing a water noise. Otherwise, there should not be a whistling noise when only the burners are on. A second thought: Many companies use a foil tape to seal air connections. What you find is that the glue dries out and the tape starts peeling away from whatever it was attached to. In the case of a furnace, this would allow air to pass by and cause a high pitched whistling noise. If that’s the problem, you have at least one air leak in your system. In that case, I would recommend having a professional HVAC contractor seal your system properly with a secondary sealant like a mastic or Hardcast cloth and glue. I suggest you contact a professional HVAC technician, such as the ARS/Rescue Rooter branch in Indianapolis, IN at (317) 390-5555, to take a look at your heating system to determine the cause of the whistling sound.