Vinegar? Bleach? Confused???
The safest and effective way to do homeowner maintenance on your drain line here in south Florida is to install a pan treatment, as described above. With the pan treatment installed, you'll constantly have specially designed chemicals circulating through your drain line, killing the bacteria that grows and clogs your drain line. Since the pan treatment contains the chemicals and treats the drain line over the course of about 6 months, your role becomes slowly pouring about a gallon of tap hot water once a month, if possible, and when your system is off.
My thermostat and entire HVAC system has shut off.
Your drain line safety switch may be triggered due to a condensation back up in your drain line.
Your drain line needs to be cleared.
There is water leaking from my ceiling/closet/garage.
Your drain line may be clogged, backing up into your air handler.
Your safety switch has failed, which is why the water is leaking out.
You need to have your drain line cleared and your safety switch replaced.
I can't find my exterior drain line.
Look in and around your bushes. Keep in mind your drain line may not be near your outside AC unit.
Last resort, your AC tech can blow nitrogen gas through your line at the air handler to locate your external drain line.