I replaced my 45 year old (still working) original furnace with an American Standard furnace about 5 1/2 years ago. Now I have a gas leak; the Nicor technician sealed a connection in the gas pipe connected to the furnace. He noticed the original gas line was being used & was crooked & could not thread properly, causing the gas leak.
Should old gas lines be replaced w/new installation? Is that "code"?