Hi, first time posting here. I inspected a gas forced air furnance that runs on natural gas, but noticed a sticker stating it was fitted for propane. It's a Trane XE 70, Model #TUS100B936A0, manufactured around 1990. Is there some easy way to tell if it has a propane converter kit installed when it shouldn't be? BTW, the heat exchanger was replaced in Nov. 2004. Download Attachment: propane or natural gas.JPG 68.68 KB Download Attachment: propane sticker.JPG 51.23 KB