This house I am looking at has a Payne split system,it is a heat pump,now the ? Is..

What year is it? And what size? The house is like 1,950 sq.ft. and the number off the outdoor unit is:PH14N00048-A and I could not see the serial number all I could see was: "X" and some other numbers.is this unit to big for this house?and the air handler has been replaced with a Goodman and the coil wasent replace.dose the coil need to be replaced?

Thanks,

Mike

4 ton unit,, no way to know with out getting it looked at by a local hvac company and they do a manual J calculation, if its to big