Being told I need to replace entire system because coil in air handler is bad
Hello, my family just moved into a new house a few months ago. We were told that the A.C. was new-ish when we purchased the home. Well, we noticed that the central A.C. would freeze up every 2-3 weeks. We'd clean the filter, thaw it out and it would run again for another 3 week period and freeze up again.
So we called a repairman out to take a look. He told us that the previous owners had only replaced the big outside unit which contains the compressor and that the outside unit looks to be installed a few years ago and was manufactured in 2003.
But he said they didn't replace the inside unit which was built in 1996 and has rusted coils and is totally filthy/gunked up. Repairman suggested that we buy a new inside unit since outside unit is relatively new and skip replacing coils.
But he couldn't give us an estimate as what anything would cost.
His boss called me today to give me a quote and said that the coil in my air handler is bad. He said that I could either replace the air handler and modify it to work with the old kind of refrigerant my unit takes - or - replace both the inside and outside units. He said that replacing the air handler is a bad idea because it has to be modified to fit old refrigerant and if either the outside or inside unit breaks the costs to repair would be astronomical due to this refrigerant issue.
Seems like it shouldn't be such a big deal to just replace the rusted coils and clean the Unit but he definitely did not agree with that plan of action. He also insisted that I replace the outside component as well, not just the inside, which dismayed me because I was under impression it was relatively new.
Am I crazy for thinking that there's a simpler solution other than replacing everything inside AND outside?
Hope that made sense, thanks!