Flexible gas line against sharp metal edge of furnace
Gas lines often enter into a furnaces’ metal side through a round hole. This hole may have a sharp metal edge that slowly damages or cuts through the gas line. As a unit gets older, the motor in the unit may start to vibrate.
This vibration causes the entire unit to vibrate, including the metal cabinet of the furnace where the gas line goes through. If the gas line is touching or gets against the sharp metal edge of the furnace, then the metal edge acts like a hack saw and slowly cuts thought the gas line. Millions of furnace have gas lines installed this way.
On new installations, a rigid pipe is now used in this area and then a flexible gas line is used from just outside of the furnace to the gas valve.
To prevent damage to the gas line, many home owners and HVAC contractors are now placing special bushings around the metal edge to provide additional protection or installing a short piece of metal rigid pipe.
Both of these actions are quick and inexpensive.
Who to consult? Plumbers, HVAC contractors and qualified handymen.
DIY home owners may improve the gas line installation themselves. Plumbers and HVAC contractors, as well as qualified handymen normally can easily do this type of work. Occasionally the gas company will provide and install a plastic bushing around the sharp metal edge at no cost.