Check the terms of your warranty to see if your compressor replacement is covered. If your warranty coverage is 5 years on the compressor, its replacement should be covered by the manufacturer for a system installed in late 2018.

Manufacturing warranties don't typically cover labor, Freon (refrigerant), freight & handling as wells as possible other charges due to the nature of the work being performed specific to your HVAC system.

What is the temperature of the air coming out the supplies? What price were you quoted to replace the compessor snd dryer? You should ask if the compressor and dryer part costs are covered under the warranty. What Carrier condenser model to you have? This will indicate if you have a 5 or 10 year parts warranty.

Which is it, a bad compressor or a leak? You need to get someone in who knows what they are doing. If the installing contractor's tech can't give you a definitive diagnosis, as to speak to the owner of the business and get the local carrier distributor involved. HVAC isn't rocket science. As posters above have said, there are standard ways of confirming (or refuting) each of these supposed diagnoses.

I was told it's the compressor. On the job order it says replace compressor and underneath it says install new filter drier with leak repair.

Why the leak repair?

The parts have a 10yr warranty per manual that came with the unit. Unfortunately labor only had 2yr warranty, so I'm out of luck on that. Initially I was quoted 1850 for the job. Now the price has gone up to $2500 because of the rise of Freon prices.

Another question I had is, can any certified HVAC company claim warranty on the compressor or does it have to be the company that installed the system?

The warranty should be yours provided you're the original owner. Consult the terms of the warranty regarding whether replacement needs to be by a Carrier dealer. The original installer may offer a warranty in addition to the manufacturer's warranty that might tip things in their favor so be sure to ask if in doubt.

The manufacturer's (parts) warranty should be good for any licensed HVAC company. They simply need an account with the local parts distributor. For labor, you're on your own.

I'd want a second (and maybe third) opinion before I'd go changing the compressor!

Another question I had is, can any certified HVAC company claim warranty on the compressor or does it have to be the company that installed the system?

Carrier is a PITA to work with for any warranty type claim(s) since as far back as maybe 8 years or so. Unless you're moving 100K or more in annual carrier equipment sales with them.

If you're moving 100K or more in annual equipment sales, your company motivation(s) aren't in the realm of warranty service & repair. Sell, sell, sell.

FAD: factory authorized dealer is nothing more than an agreement to sell new equipment, not warranty repairs. Fall below the 100K sales goal, find yourself cut off. Your motivation has to be to sell new equipment. (this is only going to get worse with new refrigerants / and R410a new equipment bans that may start as early as Jan. 1, 2025)

It could be 'some what' different in some parts of the country. In my neck of the woods (Katy, Texas) it's as I say it is. I still work on Carrier equipment, but the crap they dish out finds it's way down hill to those that own this particular brand.

Other major brands aren't much different. It's all about selling you bro. In some cases you may actually need new equipment. There in lies the rub, knowing what you need versus what you don't.

If you think a Carrier dealer is going to have your back when they lose their carrier "FAD" status by not selling new equipment? Yeah let us not think about that.

I don't care if you don't like it. I tell it like it is... if your old enough to own a home, you're old enough to handle the truth. Believing what I say on face value is a whole other story. (This is the internet afterall.)

I service the Katy, Texas area.

UPDATE: Had another tech come out (4 total now) and was told "the compressor sounds rough on start-up and pressures are flunky". Gave me an estimate for replacing the compressor and that was that.

Here is the interesting part. Two days after the last tech came out, my AC suddenly started to work "normally", or at least better. By that I mean it's keeping up with the heat. Last 3 days it has been 99, 99 and 102 today. The ac was actually able to bring the temps down to 73 degrees several times throughout the day. Whereas before, even with the temps in low 90's, the ac was not able to bring the temps below 75 until it would start to cool down outside.

What gives? Can a failing compressor exhibit these symptoms of not cooling well for a while, and then suddenly start cooling much better even though it's a lot hotter now.

UPDATE: Had another tech come out (4 total now) and was told "the compressor sounds rough on start-up and pressures are flunky".

Hard to say without actually looking at it... but if pressures are flunky as you say then it could be non condensibles /moisture inside the refrigeration system. Could be partial restriction. Could be metering device problem. Plenty of possibilities.

It may not be a compressor problem, but it could lead to one given more time to drive it into the ground.

Compressors are refrigerant vapor pumps... not air, dirt, dye, moisture pumps.

non condensibles trapped in HVAC system can cause a number of odd behavioural type issues with cooling performance, not to mention how they run / start up.

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If it's non condensibles / foreign matter and the compressor is replaced --- new refrigerant is used --- old is reclaimed and turned in to reclaim center --- compressor is installed properly and there are no outstanding issues like restriction... regardless if your compressor is /was bad or not that procedure fixes many possiblities. Could create new ones.

Skill --- is typically not involved in deal of the century type bargains. (even worse if you actually paid hard money for what you got.) My experience is sometimes in the realm of someone buying a scratch and dent unit and paying someone in beer money to help them install it and then expect the manufacturer to fix it under a MFG warranty. (I wish that story wasn't true. I talk to people what can I say... I find it amusing sometimes what people do / how they run their household.)

BUT: condemning a compressor to fix a non condensible issue is a sinking ship. (more or less why the FAD argument falls apart most of the time... they are claimed to be the experts when really all they do is go around selling new systems. Or maybe I am completely wrong and it is indeed an equipment lemon? I've seen beautiful installed systems that don't work. Sold because a deal of the century was reached is usually the reason. Maybe I am the wrong one to ask?)

Anyone can replace a compressor again and again and again... fix a wide variety of problems that way... provided of course they don't repeat the same actions over again that was done prior that may have caused the problems in the first place. I don't know I am only guessing... it may be nothing like I am saying here or maybe it is?

I have never made a living as a psychic. I have no fortune telling attributes what so ever.

"Could be partial restriction. Could be metering device problem. Plenty of possibilities."

That's why you need someone who knows what they are doing. I'm not impressed with any of the "diagnoses" you've received so far!