How to unclog an AC Drain line with a Shop Vac

The condensate drain line is an important part of your air conditioning system. If this drain line gets clogged up your air conditioner will start to leak water inside your home.

This water can cause extensive damage so the leak needs to be repaired as soon as possible. Luckily this is a really simple problem to solve!

This can be done in three easy steps:

  • Turn your air conditioner off
  • Locate the AC Drain line
  • Use the Shop Vac to remove the clog

You will need a Shop Vac (wet/dry vac) and either Duct tape or a towel.

Below I will go over each step in detail.

Turn off the air conditioner

First, turn off the AC unit at the thermostat. Next, turn off the AC unit using the breaker.

Turning the unit off will prevent any potential electrical issues while cleaning the unit.

Find the AC Drain line

Find the end of the AC Drain line located outside of your house. All Air Conditioners have an AC Drain line that runs from your air handler inside of your home to a drain location outside of your home. This AC Drain line is used to move water produced by your air conditioner outside.

If you are having trouble finding it try looking for a PVC pipe coming out of your house near the AC Unit.

Unclog the Drain

Check the end of the line

When you have found the end of the AC Drain line you can check for any blockages at the end of the line. If your line is at ground level, this is most likely where the clog is.

Get the Vacuum ready

Before we can use our wet/dry vacuum to vacuum up water we need to remove the filter. This keeps the filter from being damaged by the water we are going to suck up with the vacuum.

Connect the Vacuum to the drain line

Use either Duct tape or a cloth towel to connect the Shop-Vac hose to the end of the drain line. For the best results place the tip of the Shop-Vac to the end of the drain line before wrapping the connection. Once you have a firm seal (which may require using a hand to hold it if you use cloth) it is time to start vacuuming out the line.

Vacuum out the line

Turning the Shop-Vac on high for 10-30 seconds should be enough to clear your clogged drain line. Once you have turned the vacuum off, check inside the vacuum to see if you managed to clear the clog.

If the clog hasn’t been cleared try turning the vacuum on and off every 5 to 10 seconds. If this doesn’t clear the line, you may have to run a snake down the line.

You can test if you have cleared the clog by pouring water down the drain line access hole inside. If the water flows freely outside, you have cleared the line!

Once the line is clear, turn the air conditioner back on and see if it is still leaking. If the AC is still leaking and the line is clear, your coils may be dirty.

Once you have cleared your line, you may want to read our quick guide on how to prevent future clogs.

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