No model numbers posted on questionable system....I certainly would not spend any serious money on a repair, albeit a Goodman system. Not clear about your post and description, is the system in question a package unit or in fact a true split system with inside air handler and outside HP condenser?

IMO

tigerdunes-

Goodman unit that is leaking is a Model "GSH130361AA made in 2006. Split system with electric furnace Model ARUF36421BA. I had figured I could just replace the leaking A-coil on top of the air mover if needed. Neighbor tells me he had the same issue and was told he could not replace the A-coil on this model, have to replace the whole air mover. Especially since it is an R-22 unit. I had never heard that the A-coils were integrated and changed out with the air mover instead of as a separate piece of coil by itself.

for OP...you do have a problem...Goodman, age, R-22, leak...cut your losses and replace complete...

IMO

The units were probably registered. What happens though is that when the home changes ownership, the warranty reverts back to the standard warranty of 5 years. (Like it wasn't registered, even if it had been registered.)

The A-coil of the electric furnace can be replaced in some cases. But if you attempt to order the exact coil from the manufacturer that coil made specifically for that air handler will likely be sold for more than what a whole air handler will cost you. Oh, those pesky manufacturers. Yep, they all do it.

In some cases not all, I have been able to just change the coil many times with a different brand of coil that will fit the box of the air handler. The problem these days is that the coils are larger (more surface area) than those made just some 5 odd years ago.

So there is probably a 50/50 chance that you could just change the coil and it fit right.

Given that you just purchased the home, it's probably in your best interest to replace the system and upgrade the AC to use R410a refrigerant.

R22 also widely referred to as Freon will no longer be produced after Dec. 31, 2019, what is allowed to be produced is a very low amount that will never come close to meeting demand.

Because you have 3 systems that use R22, and you bought this home as opposed to looking to sell it... you will need to start converting these systems over to R410a refrigerant. This can only be done by replacing equipment.

Refrigerant leaks will continue to be a challenge as the price of refrigerants continue to rise the old method of recharging systems every year is a thing of the past. Those leaks have to be repaired, regardless of the type of refrigerant your system uses.

In addition to the complications listed above about changing only the coil, the units you have are heat pumps. So any coil that you attempt to change for this system would need to be a heat pump coil. Some coils are AC only without specific changes to the coil, the heat pump would never work right. This would be considered a high skill operation. It can be done in some situations... but should be left to those who have done it.

If you can't find someone like me in your area... forget about it.

Want to see why newer copper coils fail: it has nothing to do with brand. It has to do with the thickness of the copper wall. So aluminum coils are now the rage. Are all aluminum coils the most perfect thing since sliced bread? Watch the video: Copper Coils Vs Aluminum Coils. ( I service the Katy, Texas area a west suburb of Houston, Texas)