I have a question about an A/C unit installed on it's side in my attic that is leaking. Is stop leak a viable solution?

by Dean
I have two separate units installed on their side in my attic (2 blowers/evaporator coils with the condensors outside). One has no problems, the other does. I have had "mildew" accumulating in the coil that no one has been able to resolve. I now have coolant leaks. The resolution offered was to replace the unit or try stop leak for $200 w/ no guarantee. The tech tells me units on their side have more issues but the other unit is not problematic. Further, if I elect to replace, access is currently limited to 20" square. The current unit was two pieces & fit through the access but I'm not aware of a replacement unit that will work. Thoughts? Solutions?
  3 answers
  • Dean Dean on Jun 15, 2012
    These units are in my home in Northern Indiana.

  • Hi Dean, Few things and few questions. Are these in a multi family unit? You mention their side? Is it that you have a common attic between the two of you and the units were placed over your area? Leaks, There is nothing you can do other then find the leak and solder it closed. Adding any chemicals other then a florescent coloring agent that glows under a black light to help find the leak, nothing should be added to the system. If the leak is bad enough where you need to add gas more then once a year your better off replacing the entire system. As most likely you have an R-22 gas in the cooling system. This gas is no longer being produced and its cost is skyrocketing. If the leak is small and you only need to charge it once a year, then simply pay for the service to charge it and save for next year to replace it. When leaks are beginning in an older AC system, it is oftentimes not worth the expense of finding and fixing. These tiny leaks can be from a cracked pipe in the system, to a failed solder joint. A small rock from a lawn mower could have punctured the outside coil. With labor rates, cost of gas and parts, your better off changing out the entire system then trying to fix. As far as mold, if the condensate drain is been plugging, or your unit has been icing up, which it does when its low on refrigerant this icing can cause water to overflow the collection pan and get the insulation within the blower cabinet to get wet. When this happens mold will develop in this area. If mold is growing on the coil then the coil is dirty and needs to be professionally cleaned. Mold will not simply grow on the metal coils, it needs a food source, In that case it is the accumulated dust on the coil. The size of the system is not an issue. In fact they are making the interior sections much smaller every year in an effort to keep the cost down in making and to make them more energy efficient. However, to get these coils and blowers installed you need to replace the outside unit. These units must match not only because of the type of refrigerant is being used, but to get any rebates that will help offset the cost of the install. If you do not want to change out the outside system, you will be stuck with a larger less efficient system that will not qualify for any rebate programs, and you risk finding out that the leak is from the outside unit. Hope this helps you out in your decision on what to do.

  • Pete Wells Pete Wells on Mar 19, 2015
    Air handlers installed in attics are ALWAYS troublesome, if you like brown water stains on your ceiling, installing air handlers in the attic is a guaranteed method of obtaining brown water stains..