According to Homestructions, clean air conditioner drain lines by using white vinegar, bleach and water. Using an improvised vacuum cleaner or a mighty pump to clean a condensate drain line is another option.
Clean a condensate line by first checking whether the drain is clogged. If there is no sign of a slow drip, then the air conditioner drain line is blocked; therefore, cleaning is required. To unclog or clean the line, pour white vinegar to kill any algae that might be growing inside. Pour water into the drain several times to rinse and get rid of the white vinegar odor.
Another alternative method involves using bleach instead of vinegar to clean the condensate drain. Use the same procedure. However, bleach should not be used during colder months as it can damage the pipe.
Also, another effective way of cleaning a condensate drain involves using a mighty pump. Use a mighty pump to blow out the debris that is causing the clog. Make sure that you connect the pump outlet with the condensate line opening correctly before you begin. Lastly, use an improvised vacuum cleaner to get rid of dirt or debris that is clogging the condensate drain. To achieve this, use an adapter to connect the vacuum cleaner with the condensate pipe. Vacuum clean to remove any debris. A vacuum with powerful suction is required for this exercise.