Carrier equipment comes with a 10 year parts equipment provided the installer registers the equipment at the time of the installation. If he does not, then it may only be a 5 year warranty. In 2010 it was possible to buy a 10 year labor warranty directly from Carrier. I am not 100% sure, but I believe only Carrier Factory Authorized Dealers are paid the labor charges for the labor warranty. If you can't find the paper work, you should be able to call Carrier and give them the serial numbers of the condensers. The warranty should be in their records. You don't need a service contract. You should do period maintenance in order to prove the equipment is being maintained in case their is a dispute with Carrier. How big is your house? I know temperatures in Arizona can easily hit the low 100s, but 10 tons of cooling is still a lot. Have an evaluation done of the duct work. My suspicion is the duct work is too small and may have caused the compressor to fail prematurely. Most houses don't have duct work large enough for one 5 ton unit. Duct work for two 5 tons units would be an impressive installation.

I'd take the money and run. No current buyer really cares what you paid for it 10 years ago. To help you part with it and put things in perspective, if your current set originally cost $1200 and you've had it for 10 years then your per year cost was only $120 or about 33 cents per day. Anything you can get out of it is just a discount on your new purchase. But I know where you're coming from. I have a 30+ year old dining set that I'm struggling to part with. But my issue is finding something else that is the size I need in a style that fits and a quality I like. Guess I should just list it and once it's gone I'll be forced to be less picky.

Why not keep it on the market until it sells, regardless if it is fall or winter? I vote no for the renter. I am speaking as someone that previously was a landlord. Most landlords say never to rent to family or friends(coworkers included) or family of friends or friends or family. Else you might lose that friend forever when they move out leaving urine stains from pets that they say they never had. Then they badmouth you to others saying you are charging them for something unreasonable. Folks will take sides. If you decide to rent to this person anyway, make sure you have a written contract, security deposit and also do a credit check before agreeing to rent to this person, even if you trust them. If their credit is bad, don't do this. Also take pix of everything before they move in. Write up a list that describes the condition of everything(each appliance, carpet, cabinets, windows, doors, trim, faucets, lawn, driveway, etc) upon move in and have them sign it. This is a must. Don't consider renting if they have pets, no matter how clean. Don't allow pets to show up after the fact, or other folks that are staying there for months at a time. Some renters bring in 5 other people later and if there is no teeth in the rental contract, you can be stuck with a house full of people. Realize it is very easy to find renters - but the trick is to pick the good renters that will pay and will not destroy the place or cause issues. Rental history, background checks, employment verification, credit checks, and just plain talking to the prospective renter and their prior landlord will assist with weeding out the renters. tricky tennants have friends pose as prior landlords, and tricky tennants know the landlord tennant laws well - just enough to trick you. You need to know the landlord tennant laws in your area. Lastly, some potential buyers might think less of the home if it was used as a rental. And you likely will have to fix/clean/paint after the renter moves out. Go to mrlandlord dot com to read everything about being a landlord. That site is used daily by landlords. I suggest you post the same question there. They will give you good info. To see the forum area of that site, click on the area that says something like Landlord Q and A. Landlords post there often. It is some very intersting reading and is a must read for anyone that considers being a landlord, even for a month.

@A K LOL, a friend sold a house with a pool table in a second floor game room and left if for the same reason, too hard to move. The listing said, "Fun pool table does convey!" The buyers loved it. BTW, my experience with high priced items ($500 or more) on Craigslist has been abysmal. Lots of scammers out there offering to pay later (even over pay) if you'll just hold it for them and BTW, let's communicate with mobile phones...meanwhile they want your mobile phone number so they can sell it. A thousand robo calls later, no sale. Maybe it's just my market, but beware. Cash only, communicate only thru Craigslist email. When I post that in my listings, I never get scammers. I don't often get offers on high priced items, but at least when I do, they are serious. All the best to you in your new home!