I have dual York heat pumps, two VS air handlers with a common return. They are not twinned and they are not the same size (one is 3 ton the other 4 ton). Based on other posts, I see that the returns must be separated.
So far I have not had blower failures but I wonder what failure mechanisms are likely with this setup? Could it impact the heating capacity of one of the units or is it primarily an issue of one blower possibly rotating in reverse due to the other unit's suction?