# Adding Two Stage AC Compatibility To Existing Furnace



## Gus (6 mo ago)

Looking to better understand why a new two stage compressor AC would not be compatible with an existing furnace. The impression from sales is that there is old electronics that would prevent second stage functionality (and therefore efficiency) from being realized with the new combination. Lacking the compatible communication effectively locks in one stage.

New Carrier model 24TPA7 with two stage compressor replacing 14 year old Lennox XC14-024-230-02 and mating to a Lennox CX34-31B-6F-1 (with 2-stage blower).


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