This may not be of interest to most on this board but I thought I'd post it because I'm sure it affects some of us.

carrier which owns bryant and payne furnaces has had some trouble with there secondary heat exchangers failing pre-maturely on there 90% eff models. especially on the models converted to use propane.

I'am by no means a expert on this situatition as a matter of fact until a week before xmas I didn't know anything about it until my bryant furnace started triping the roll out switch and was blowing cold air.

apparently at some point carrier decided to change there secondary heat exchanger from stainless steel to regular steel with a coating on it, well guess what? the coating is coming off.

Below are some pic's of my 11 year old bryant plus 90 furnace.




The heat exchanger is on the the floor to the right




this is a view looking into the secondary heat exchanger the part with all the rust.







Now you don't have to know anything about furnaces to look at this pic and see all the rust and corrison, the flue gases are suppose to flow thru those slots.