I have a 20 year old Rheem 92% eff furnace and AC system that may need to be replace. On Saturday my my wife asked why it was 80 degrees in the bedroom. The fan was set to the "on" position so it was running, just no cooling. Went out to the compressor and it was not running. Took the cover off and found that the shaft from the cooling fan had corroded and it fell off, so I guess the unit overheated and tripped. Killed the power and waited a while and tried to see if it would start up, but no luck. Would not run it like that, but just wanted to check it out. Could not find any resettable overload device, and the breaker was not tripped. The utility company is coming to look at it today, but I suspect a new compressor may be needed. If so, I would replace the entire system.
Here is the issue, I have never been happy with the system. We have a Carrier Infinity system we are very pleased with in the larger part of the house. This unit covers four bedrooms and a work shop. The workshop and one bedroom and on a lower level and three bedrooms, one of which has 14 foot ceilings is on this unit. It was originally setup with Honeywell dampers with thermostats upstairs and downstairs, but that never worked well and for many years has just been controlled by the upstairs stat with the dampers manual set for best balance. So the question, what can I install to get the zoning to work better. Also I was never satisfied with humidity removal, perhaps the unit is too big. I believe it is a 2.5 ton system on a 75,000 BTU/Hr furnace.