When you turn your furnace on and hear a knocking or clanking noise, it is known as oil canning. Oil canning or tin canning occurs when the pipes, or ducts, running from your furnace shift around and vibrate or rattle against the connection site in your home.
When your furnace kicks on and off, the ducts fill with air, expand, and pop. And then, as the furnace goes off, the air rushes out of the ducts, and then they sag, and they pop again. It’s the sort of metal banging sound as the ducts expand and contract. To stop the furnace from oil canning is to add another piece of metal on top of the duct where it’s making the noise.
Things You’ll Need
- Rubber gaskets
- Utility knife
- Turn on your furnace and pay attention to which ducts, or pipes, are knocking or shaking, leading to the oil-canning noise. Make a note of which ducts are the area of concern.
- Tap around the connection site gently with a hammer. When the connection site has a wooden wall against a metal connection, it is a common area to hear the noise. Making small dents along the duct’s connection area will tighten the connection and prevent it from being able to wobble around as much. This can also happen with a concrete wall.
- Disconnect the pipes, or ducts, at the connection site and insert a rubber gasket, or rubber pads, between the metal and the wall. When the pipes and ducts vibrate, the rubber will reduce the noise and possibly eliminate it. The disconnection procedure may vary depending on how the pipes or ducts are connected. It may be as simple as using a screwdriver and unscrewing it, or they may have a sealant holding the connections together, which would require a utility knife to cut through the sealant to loosen it.
If you still have noise issues, hire a professional to investigate the system. They can reroute your ducts to eliminate the noise or if it is possibly an issue with the furnace itself.
While the noise from an oil canning furnace can be annoying, it does not mean there is an issue with your system. But, it is always best to have a professional inspect your entire furnace system to ensure it is in good working condition. Once you know the issue is not your furnace, you can reduce or eliminate the oil canning noise.