How do I unclog my air conditioner's drain pipe?

To unclog your air conditioner's PVC drain pipe effectively, follow a simple step-by-step process starting with turning off power to your HVAC system at the thermostat and breaker for safety. Locate the T-shaped PVC vent opening near your indoor air handler and remove the cap, then pour a mixture of warm water and distilled white vinegar or hydrogen peroxide down the pipe to help break down organic slime. If the line remains blocked, go outside to the exterior wall where the drain pipe terminates and use a wet-dry vacuum to form a secure seal over the pipe opening, running it for a few minutes to suck out the stubborn clog, stagnant water, and debris. You can also use a specialized pressurized CO2 clearing tool to blow out remaining obstructions. Finally, pour a gallon of clean water down the indoor access tee to verify that the line is completely clear and draining freely outside.