My AC drain line is blocked. How can I clear it?

Clearing a blocked air conditioner drain line requires a few straightforward steps and basic household tools to remove accumulated algae, mold, and sludge. First, turn off the power to your HVAC system at both the thermostat and the main circuit breaker to ensure complete safety while working. Locate the T-shaped PVC vent or access opening near your indoor air handler and pour a cup of warm water mixed with distilled white vinegar or hydrogen peroxide down the pipe to loosen minor organic buildup. If the line remains completely blocked, go outside to the exterior end of the drain pipe and use a wet-dry vacuum to create a tight seal and suck out the stubborn clog, standing water, and accumulated debris. Alternatively, you can use a pressurized CO2 cartridge tool designed specifically for HVAC lines to blow the obstruction outward. Once cleared, pour a gallon of clean water down the indoor access point to verify that it flows freely out of the outdoor exit.