The P-trap is the curved section of pipe you see under your kitchen sink, shaped remarkably like the letter “P” (which explains how it got its name). 

Many homeowners who deal with clogged or slow draining sinks don’t know that the P-trap can actually get bogged down with soap scum, hair, grease, and other debris that may have accidentally fallen down the drain. In your entire sewer system, the P-trap is the most common place to find a clog.

Knowing how to clean out your P-trap is a very useful skill as a homeowner, so let’s cover how to clean P-trap under a sink—specifically how to clean P-trap under a kitchen sink—in a few simple steps. 

Here are seven steps for how to clean your P-trap.

Cleaning a P-Trap

Knowing how to clean a P-trap can be incredibly helpful since you won’t have to wait on your plumber’s schedule or waste money on harmful chemicals that might not work and may end up damaging your sewage system. 

Here are seven DIY steps to help you learn how to clean P-trap under a sink:

1. Clear the Area Under Your Sink

Even if you’re a professional and already know how to clean P-trap under a kitchen sink, it’s still important to clear out the area. To properly clean the P-trap, you’ll need space, and you’ll want to be sure to get everything out of the way.

You don’t want anything to get damaged or soiled with dirty sewage water.

2. Place a Bucket Under the Pipes to Collect Water

Place a bucket or a large dishpan underneath the pipes once the area is clear. As you’re learning how to clean P-trap (or doing any under-sink plumbing), keep in mind that a bucket to catch water leakage is important.

If your sink is backed up or even slow to drain, you can expect there to be a lot of water waiting to pour out as you clean the P-trap.

3. Remove the Coupling Nuts Attached to the Drain Pipe

Once the bucket is properly placed, start removing the coupling nuts attached to the drain pipe. The nuts on each side of the trap must be loosened, which may be possible to do by hand.

If your plumbing is old or the nuts are too tight, however, then you can use a pair of channel lock pliers or a wrench to loosen the nuts. If you want to avoid scratching the metal, you can use a strap wrench or wrap a rag over the nuts before wrenching them loose.

Be prepared for the process to get messy. Water will likely begin draining out into your bucket at this point.

4.  Plug the Pipe Coming From the Wall

At this point in the process, you will want to plug the pipe coming from the wall. You can do this by stuffing a rag into the pipe, though you should make sure it doesn’t get lost or pushed too far down where it can’t be easily retrieved. This is to block any sewer gas from coming up the sewage pipe and into your home.

5.  Clean the Inside of the P-Trap

Now you can get to the part of the project you’ve been waiting for: cleaning the P-trap. To get a clean P-trap, you’ll want to use a bottle brush or another tool to clear out any debris found inside the trap.

Gently clean the piece coming from your sink and remove any dirt and grime that may be present in the pipe on the wall as well. If you want to, you can take the P-trap to another sink in your home and rinse it out.

Be sure to clean out all dirt, grime, soap scum, and hair trapped inside to prevent another clog from occurring anytime soon.

6.  Reassemble the P-Trap

Once you have a clean P-trap, it’s time to put it back together. Reassemble the P-trap and replace all the nuts as they were at the beginning. Leave the bucket or dishpan underneath the sink until you’ve tested the piping.

7. Run Water to Test if the P-Trap Leaks

It’s time to test it to be sure you did your work correctly. Run water for a few minutes down your sink drain and check for any leaks. If everything looks good, remove the bucket or dishpan and the job is done.

Should You Use a Drain Cleaner to Clean a P-Trap?

Using a chemical drain cleaner on your P-trap should absolutely be a last resort. While some drain cleaners are effective at removing clogs in drains, most of them are harsh on your plumbing and can end up causing more harm than good.

Some cleaners can corrode your piping and lead to massive plumbing expenses down the road, so it’s best to use safer methods when cleaning a P-trap.

How to Know You Need a New P-Trap

In most cases when your sink is clogged, cleaning the P-trap is enough to get everything working again, but in other cases, the P-trap may need to be replaced. How can you tell the difference?

Check to see if your P-trap is leaking water. If the nuts are properly tightened, but there’s still a leak coming from the P-trap itself, that means it’s malfunctioning or corroded and needs to be replaced.

If the P-trap is visually broken or corroded on the inside, it should be replaced. As you’re cleaning your P-trap, check the integrity of the trap itself for any signs of breakage or wear.

Contact the Plumbers at John C. Flood

If you can’t figure out how to clean P-trap under a sink, or if your sink keeps getting clogged despite cleanings, call the plumbers at John C. Flood. We can help you with all your sink clogs and any other related plumbing issues that may arise.

You can easily schedule your service online or speak with our professionals for more information about your plumbing.

John C. Flood, Inc. cannot be held liable or responsible for any personal or property damages incurred if the end-user attempts any of the aforementioned DIY tips and instructions.