What brand is the best and most reliable central heat and Air conditioning system (not window unit)?

Having installed all the popular brands for 10+ years I would have to say that " Bryant Evolution" TOPS my list. The user interface (Thermostat) is like a mini computer that interacts w/ the Furnace and Condenser enabling the service person to look at the Thermostat and gain Access to the Fault Codes and be able to tell Exactly what's wrong with the system within 5 minutes. enabling you to save money. The system is 2 stage saving money on heating and better help you dehumidify your house in the cooling season.

Lennox at what point was at the top in mind since they were always leading on the innovative side of things and their equipment held up well. Few examples would include the Pulse furnace which came out about 25 years ago is still just as efficient as brand new equipment today, although the heat exchangers had issues thats another story, Another story can be the number of cooling coils still in operation today that have lived 20 some years without occuring significant leaks, or how about the simple approach method for checking a charge on an a/c unit. No one else I know of had the engineering into their systems like Lennox did. Now days so it seems everyone is on a similar schematic or gameplan with their furnaces, heat-pumps and a/c units. Meaning the majority of parts come from a 2nd party ie, copeland scroll compressors, GE variable speed motors. Controls from White Rodgers, Robertshaw, Honeywell. The basic operation of anything new regardless of the manufacturer is pretty close to one in the same for me, obviously a few variations here and there but pretty much all along the same lines, just a matter of how well the equipment is installed and how durable some of the material is. With that said this is how I'd rank equipment. And in my opinion there is really only 2 categories. 1)Equipment I'd put into my grandma's house 2) Equipment I wouldn't take if it was given to me 1) Lennox, Trane/A.S., Carrier/Bryant, Rheem/Ruud, 2) York, Goodman, anything else

There have been so many new designs from all of the manufacturers in an effort to meet the new SEER levels that it is hard to be sure which is currently the most reliable.

Some of the higher SEER designs are so complicated that they just beg to have problems.

I would not buy any unit right now without a full 10 year warranty.

It is hard to stop a TRANE. Had mine installed 5 years ago and have never had any problem with it.

As has been stated Trane is really the best, but Carrier and Lennox are also comparable.

TRANE