Was yours a high-efficiency furnace installed 7 years ago? If so, don't blame Carrier. 7 years ago, high efficiency furnaces had a lot of kinks. It just happens that Carrier was the only manufacturer making the high-efficiency. Now, all the cheapie furnaces are making them, because the technology has come far. But don't blame Carrier. They were at the forefront. Without their models 7 years ago, we wouldn't have the much less expensive and much more reliable models that we have now.