Introduction: AC Drain Modification

I’ve always had a problem with AC Drains clogging with algae causing a back up of water to flood the house.

The accepted method to deal with this problem is liquid bleach & a pipe snake.While this will work, most the time, it’s not a long term solution.After just a month or two, I was back in the attic, doing the same thing again.I wanted something better.

My requirements for this solution were 3 basic things:

2.Long term

After searching for something better, I was disappointed not to be able to find anything better.Then one day while I was working on my pool, the solution came to me.I needed a chlorine trap.This whole time the answer was floating around in my pool.I needed a basket to hold chlorine tablets for the AC.

By adding an access port in the drain line of the AC, I could then put chlorine tablets into the trickle of water.The water will dissolve the tablets & carry the chlorine throughout the entire drain line.The only thing I have to do now is refill the trap about every 6 months.

Parts Needed:

1.Chlorine Tablet (Pool or toilet)
2.PVP Pipe
3.PVP Cement
4.PVP Joints & Tee with cap


2. Wench
3.Tape Measure
4.Teflon Tape

This Instructable includes the rebuilding of the AC drain pipe.Not all situations will need the rebuild, use your judgment.When I reviewed my pipe, I realized that I needed more pipe space then I had available.I will have to rebuild the whole setup.

Step 1: Plan

I knew that I had to add some length to the pipe in order to get my trap into place.  So when I rebuilt the pipe I added a few more inches to it.

The top part is the old pipe setup.  The bottom part is the new setup.  I wanted to keep the basic design the same.  The old design was easy, simple, & efficient.

Step 2: Cut & Dry Fit

Now that I know the lengths required for the new design, just mark the PVP Pipe & cut with the saw.

Sand all the cut edges to get rid of any remaining material. 

Dry fitting is always an important step.  This ensures a good build & proper fitting before we head back into the attic.

Don’t forget to cut & test your mesh.  You want a nice snug fit in the pipe, but you don’t want to impede the flow of the water.  I used plastic mesh in this build, but any mesh that can withstand the chlorine will do.

Step 3: Removal

To remove the old setup, just saw through the pipe, & unscrew from the AC unit.

This was easier said than done.  Lots of elbow grease & a couple of wrenches finally worked the old connector off.  Please be careful, as for you do not want to damage the metal pipe coming out of the AC.

Step 4: Installation

Start by applying Teflon Tape to the threads of the connectors at both ends & screw the end pieces in place.  Then began cleaning & gluing the rest of the new build from the end connectors.  The glue will set fast, so make sure you have good placement before making the final connections for the joints.

Step 5: Chlorine

Grab your tablet & crush it into small ¾ to 1 inch chunks.

One 3 inch pool tablet will provide you more than enough pieces for a year.  Just fill up the trap with the pieces & cap it up.  You don’t have to have a tight seal on the cap as for the drain is not pressurized.

Put the cap on & leave it be.  The flowing water will dissolve the chlorine & the chlorine will keep your pipes clean.

After installation, go check it in a couple of days to ensure that everything is working properly.  The water level in your drip pan should be your first indicator.  If the water level has dropped, then that is a very good sign.

I want to thank you for viewing this Instructable. 

It is my first.  I love this site & I’m ecstatic that I have something I can contribute to the site.

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