Pinging/Knocking noise from wall
We just bought a house and have noticed a knocking/pinging noise from the wall when the gas heat turns on and after it turns off it is even louder. I'm prettty sure the vent is a direct run from the heater in the basement thru the wall in the family room (this wall backs to the attached garage) to the bedroom upstairs. From the bedroom it almost sounds like someone is throwing a ball against the side of the house. The noise is louder when the temperature is colder. I'm guessing it is the metal expanding and contracting... anyone know of a fix for this issue?