Heat Exchanger

[mcmitchell]

We have rental property with a Coleman Presidential III 7900 Series and has an AC Blower
7900-6821. Repair guy today told me the heat exchanger is "shot" and that we need to buy a brand new furance. I found one in the classified that has been used 1.5 years and is a Model M1MB-077-AAW which I think from looking on here is a Nordyne. Will this switch out properly with the existing AC and blower? I'm told replacing the heat exchanger is not an open....

[Robert]

It might, but can't say without being there. If it fits dimension wise and has right amount of airflow for that furnace.


Also need to be sure replacement furnace meets needed btuh for the home and matches old unit.


I would have a Manual J Load Calculation done to know size needed. Then find the furnace and see if current blower meets the needed specs.


With that said, buying a used furnace is not something I would advise, too many safety variables that could come back to haunt you.


Thanks,
Robert