You failed to mention what failed on the coil/cooling system-

Holes?
Fins?
Leaks?
Obstructions?
Drain pan?
????????

Every one of them failed in the same way. We were told they "sprung a leak" and the freon slowly leaked out. Thanks

are they sure it is the indoor coil leaking? did they show you the leak? one indoor coil maybe two but five if they do not show you the leak they may be guessing and there ma be a leak somewhere else. what brand unit is it? 5 coils in one year that shows a leak up that fast. it sounds to me like it may be a leak on the high pressure side. it is a big leak to show up that many times in less than a year

You are living a service nightmare and for the rest of the individuals in my industry I apologize I have a hard time believing that 5 coils would leak, in 10 years yes but not in a short time frame I wish I could come there and fix this for you just to show you that everyone is not like what you are experiencing as a matter of fact if you are in the southeast I will

Here is a link that might be useful: Air Conditioning and Heating Repair Made Easy

Are there any cleaning solvents stored in the area where the air handler is located?

The link below discusses the corrsion of indoor coils.

Here is a link that might be useful: Formicary Corrosion

Thank you for the article. Although it was not what I wanted to hear. We have no solvents near the air handler, but we do have a wood floor. If that is the problem, I'm not sure what to do about it. I can't imagine having to replace it.

did they show you the leak in the inddor coil. i dont believe that five coils went bad in less than a year. you are not the only person in the world with hardwood floors. think about it. i dont think they found your leak. i think there is a leak somewhere else. and they are just guessing it is in the indoor coil. i think you need to find a new company that can fix your unit.

Did they match it to the outdoor unit? What brand is the equipment? Sounds like they aren't giving it a very good diagnosis--they need to find out WHY the coil starts to leak.

This is very frustrating. They did show us the bad coils. Every time (always the same part). They replace it and in a year or so, have to replace it again. We can see that it is the same part, so the leak must be in the coils or the unit wouldn't cool for a year or so with the new coil in. It is a Goodman 13 seer, 4 ton unit, in a 1700ft, one story house. The neighborhood is tract housing and all are about 8 years old, only 4 floor plans and no one else is having this problem. The same company installed them all. HELP!