re: Replacement parts for American Standard Central Heat Unit UM24-6 Home › Forums › Archives › Old Bulletin Board Archives › re: Replacement parts for American Standard Central Heat Unit UM24-6 This topic has 0 replies, 1 voice, and was last updated 26 years, 9 months ago by william h orman. Viewing 0 reply threads Author Posts 1 Feb 1998 at 1:49 am #282801 william h orman Anyone that can help us find a heat exchanger and gas valve knob for a 1970 model UM24-5 American Standard central heating furance. Author Posts Viewing 0 reply threads The forum ‘Old Bulletin Board Archives’ is closed to new topics and replies.