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How To Unclog An AC Drain Line: A Minneapolis-St. Paul Tech Answers

A clogged drain line can lead to puddles of water around the indoor unit of your AC, and even cause your system to stop working altogether. If you feel up to the job, we’ll walk you through the steps on how to clear your drain line.

Here’s what you’ll need:

  • A wet/dry vac
  • A thin-wire brush
  • Rags or small towels
  • Bleach
  • Rubber gloves
  • A Plastic funnel
  • Duct tape
  • 30 minutes to an hour of time

Don’t have the time or equipment for the job? Let a professional clear the drain line for you.

Schedule an appointment today

Step #1: Turn off your HVAC system

Cool vs heat thermostat setting in Minneapolis-St. Paul, MN

Turn your thermostat to the OFF position

Next, go to your electric panel and find the circuit breaker labeled “AC” or “air con.” Flip the breaker to the OFF position.

AC Breakers found in electrical panel

Look for the AC breakers on your electric panel

Step #2: Locate your drain pan

The drain pan is located under the evaporator coil in the indoor air handler. The purpose of the drain pan is to collect condensate that forms when warm air passes over the cold evaporator coils. If you see standing water collected in the drain pan, it’s a sure sign that the line is clogged. Empty the water in the drain pan and proceed to Step 3.

Step #3: Find the vent tree and clear any indoor clogs

While you’re inside, look for the vent tree, which is the PVC pipe that connects your drain line to the drain pan.

AC drain line

The “vent tree” part of the drain line

Remove the PVC cap from the vent tree and look for any visible clogs. If there are any, use the wire brush to dislodge the clogs.

Then, slowly pour one cup of water and one cup of bleach down the drain line using the plastic funnel.

Safety note: We recommend wearing rubber gloves when handling bleach to protect your skin.

If the water and bleach solution start to fill up the line, stop and continue with Step 5. If the cleaning solution seems to be flowing naturally, wait 30 minutes to let the cleaning solution eat away the clogs, then go to the next step.

Step #4: Go to your drain line outside

Condensate is carried out of your home via the drain line. You’ll usually find the drain line near the outdoor condenser unit.

drain line condensate line

The drain line exits your home near the outside AC unit

If the bleach and water solution worked, you should see a fresh puddle of water under the outside drain line.

Don’t think the bleach and water solution cleared the clog? Proceed to Step 5.

Step #5: Use a brush or wet/dry vacuum to clear the clog

If you think the drain line is clogged outdoors, you can start by using the metal brush to try and clear any clogs located near the end of the line.

Hint: You’ll know you cleared the clog if you see debris and water exit the line.

If the clog is further up the line, you’ll want to use the wet/dry vacuum to clear the clog.

Start by attaching the hose on the vacuum to the end of the line. To make the hose fit nicely around the pipe, you may want to use duct tape to attach the hose to the line.

Next, turn on your vacuum and let it run for a few minutes to suck out any debris that’s clogging the drain line.

If that didn’t clear the clog, it’s time to call a professional. They’ll have special equipment to clear the clog for you.

Step #6: Rinse the drain line

If you think you cleared the clog, go back to the indoor unit and go to the vent tree from Step 3. Take a few cups of water and pour them into the PVC cap. The water should drain outside as normal.

Tip: If you’re working alone, you can place a bucket under the outside drain line to verify water is draining properly.

If you don’t see that water draining out of your system, it means the clog is still there and you’ll need to contact a professional for further assistance.

Want a Minneapolis-St. Paul tech to clear the clog for you?

Schedule an appointment today

We can help! Our highly-skilled technicians can get the job done for you in no-time. Visit our AC repair page to learn what to expect when you hire us for the job.

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