I know this topic had been covered before, but I was not able to resolve my problem. Please help. I have an a/c technician came out and look at the overflow of water out to the outside of my house. He tried to blow freon into some kind of tube in the attic next to the inside a/c unit. He said he put some liquid that is stronger than bleach in but did not help. He said I will have to get a plumber out to check other clog. About 6 months before this, I have another a/c technician came out because of the same issue. This guy actually went inside the inside a/c unit and drop some pills inside. He said this will desolve the algae. And sure enough the water stop overflow through the tube outside of my house, but for what seems to be a very short period of time. While he was out, I have asked him how long before I need to get the pills put inside the a/c again. He said service the a/c once a year, that should take care of it.
Can someone please tell me what I should do? How can I prevent this happen every 6 months? What causes this and what can I do??? Please help.