Uh-oh! There is water everywhere and the A/C just shut off

On occasion (especially when an A/C is working too hard) your drain line will get clogged, overflow your drip pan and spill all over the floor before your T-Switch engages. If you don’t have a T-Switch then you unfortunately will just have a big mess all over your floor. Your drain line will clog up with all kinds of bacteria and other crud, especially when there are too many twists and turns in your line.

Regaining order

You can try to undo the clog with a plumber’s snake (auger), which can be very difficult to do again depending on the pathing. Every elbow on the line makes it really hard to navigate blindly down the line. Therefore this is good for minor clogs, but sometimes it still doesn’t open up the flow entirely, however it does help break up crud on the line. Therefore regardless of how bad the clog is, I recommend using an auger to break up the clog first. However when using an auger isn’t enough what do you do?

Flushing out the drain line

Under no circumstances should you ever use a product like Drano or any other clog removing liquids – this can be very dangerous for you and could cause corrosion on your lines. These clog removing liquids create heat when they react with water. Additionally you don’t want getting this on your skin while working with an auger – so please use safer liquids such as dedicated A/C drain line cleaners.

Recommended drain line cleaners

These products can be found at Homedepot or a similar home supply store. I actually recommend purchasing a bottle of the dedicated cleaner for the first cleaning, a funnel and a bottle of cleaning vinegar that you can use to keep refilling the empty bottle of cleaner. This way you have a constant way of pouring the same amount of cleaning fluid each time. Lastly you can also pass water through the drain line to make sure it isn’t clogged anymore or to test how fast water is draining.

Web – AC Line Cleaner for Air Conditioner Drain Lines


HDX 64 oz. Cleaning Vinegar


Making drain line cleaning easier on yourself

After you have snaked the line and poured some drain line cleaner to continue breaking up the crud in the line – it is time to forcefully clear the line of all the unwanted crud in the line. Don’t work hard, work smart – therefore I have come up with a very inexpensive way of doing this. Of course it assumes, as a homeowner, you already own a shop vac that has a reverse function (blow versus suck – stop giggling) and some basic tools such as a hack saw.

In order to easily clear your drain line, you will build a jig that will connect to your shop vac via a flexible coupler (the pictures explain everything). To build the jig I put together with parts I had lying around you would need:

  1. Two 3/4″ PVC couplers
  2. A short length of 3/4″ PVC pipe schedule 40 – such as a pre-cut length of 1 foot
  3. 3/4″ 90* elbow
  4. Clear vinyl tubing that will fit over a 3/4″ 90* elbow – this part can be replaced by anything really, I just had this on hand. However it is great for viewing what is happening on the line.
  5. Hose clamp big enough to fit around the vinyl tubing
  6. 1-1/4″ flexible coupler
  7. Hacksaw for cutting the PVC
  8. PVC primer
  9. PVC cement
  10. Shop vac for performing the final operation

Here are the basic steps involved:

Modifying the drain line


  1. Locate an optimal location on the drain line where you can comfortably work on the drain line when you need to clear the drain line.
  2. Cut the line
  3. Install one of the couplers on the line
    1. Use the male part on the outlet – the line that goes outside of your house
    2. Use the female part on the inlet – the line that comes from the A/C drip pan

Creating the jig

Jig_assembly Jig_assembly_disconnected

  1. Cut a short piece of PVC – you determine the length, I recommend keeping it short
  2. Connect the Female side of the coupler to a piece of PVC with primer and cement
  3. Connect the other end of that piece of PVC to the 90* elbow with primer and cement
  4. Put the hose clamp on the 90* elbow, do not tighten it yet
  5. Cut a length of clear vinyl tubing
  6. This part is kind of difficult, force the elbow into the vinyl tubing
  7. When the parts are joined, close the hose clamp over the vinyl tubing where it is overlapping the elbow
  8. Put the 1-1/4″ coupler at the end of the vinyl tubing
  9. Tighten the provided hose clamp – not too tight

Congratulations you are ready to clear your line and now that you have done all this work it will be much easier next time. Literally plug and play.

Forcefully clearing the drain line

  1. Connect your jig to the drain line using the couplers. This is why it is important to use the right sex on the drain line.
  2. Connect the other end of the jig to your shop vac.
  3. Make sure your shop vac is configured for blow
  4. Put on some ear muffs or something to not have to listen to all that noise
  5. Turn on the shop vac
  6. Wait like 5-10 minutes
  7. Go check the exit portion of the drain line outside – there should be an unholy mess on the other end and sometimes a foul odor
  8. Turn off the shop vac
  9. Remove the jig
  10. Re-connect the coupler to complete the drain line
  11. Pour water down the line and make sure it drains quickly
  12. If it does not drain quickly repeat the above steps until your line is cleared. If you are having a lot of trouble with the water draining then you need to pour cleaner down the line and let it sit for 20 minutes. Then try clearing it again with the jig.


That’s all there is to it. This work will pay off the next time there is a problem and clearing your drain line will be easy from now on. Make sure to get pan tablets and use them as suggested on the packaging. Make sure to pour drain cleaner after time you change your air filter. I recommend changing your air filter every month. Most filters are rated for 3 months, but they are cheap enough where you can buy 12 for the year and just save your A/C’s coils the harm that dust causes. Filters are cheap, repairs aren’t.

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