The truth about the carrier secondary heat exchanger bulletin
If your furnace is acting up, you've likely stumbled across the carrier secondary heat exchanger bulletin while trying to figure out why your house is freezing. It's one of those things you don't really want to know about until you absolutely have to. Basically, if you own a high-efficiency Carrier furnace (or one of its sister brands like Bryant or Payne) made between the late 90s and the mid-2000s, there's a decent chance this bulletin applies to you. ...