Where is the P-trap in my house?

Author: Dr. Duane Carroll  |  Last update: Tuesday, December 2, 2025

The P-trap is the P-shaped section of pipe in the line that runs from the bottom of your sink to the wall. It's shaped this way to trap sewer gasses and prevent them from coming out the sink as well as to catch debris that's been washed down the sink, such as hair or food scraps.

Where can I find a P-trap?

It's the strongly curved portion of piping under the sink. It's called a P-trap because the bend makes it look similar to the letter P turned on its side. It also looks like a U or a J when it's not on its side.

How do you tell if a P-trap is clogged?

A blocked p-trap will cause water backflow to occur. The first sign that your p-trap is clogged is when the water in your sink takes longer than average to flow down the sink.

How to locate a sewer trap?

The easiest way to find the sewer trap is to locate the fresh air inlet pipe which is typically located near the front wall of your house. The fresh air inlet outlet is also on the outside front or the side of your home, and it will be exposed and covered by a grating.

What does a P-trap look like?

P-traps, named after their shape, contain a u-shaped bend that filters wastewater as it enters a plumbing system. The trap is connected to a sink, bathtub, and shower with a J-bend on one end and exits into your drainage system. The J-bend is the section of the p-trap that resembles the letter J.

How Do P-Traps Work? | Spec. Sense

How to clean a P-trap without removing it?

Pour some baking soda down your drain and then pour boiling water down after. Sometimes this will clear the clog. Use a plunger on your sink drain to try to force the clog out of the trap.

Does every house have a sewer trap?

If your house was constructed prior to 1989, there's a strong likelihood that it contains a house trap or sewer trap, a plumbing device used to 'trap' gases in the sewer system so that they do not seep out into the home's interior. Today, these devices are obsolete.

Where is the sewer line on my property?

You'll usually find it outside, about 1 to 3 feet from where your house meets the ground. Look for a pipe sticking up with a cap on top that might have a square knob or notch for turning. Sometimes, this cleanout pipe isn't immediately visible because it's inside a plastic box that's slightly buried.

How do you access a drain trap?

That is simply done by undoing the two threaded plastic nuts at each end of the trap and connects the bottom of your sink to the pipework and removing it . You can then clean the trap under a tap , but not the one you have just removed the trap from .

How do you unclog a drain beyond the P-trap?

Kitchen Sink Clogged Past P Trap: How to Fix
  1. Step 1: Baking Soda and White Vinegar. These common pantry items double as superstars of the DIY world. ...
  2. Step 2: Follow Up with Hot Water. Next, run hot (not boiling) water and see if you've conquered that clog. ...
  3. Step 3: Plunge the Sink. ...
  4. Step 4: Unscrew and Clean the Sink's P-Trap.

How do I know if my underground drain is clogged?

If you notice water gushing back out from the drain pipe or leaking out from the seams on the adapter, that is a sign that there are clogs in your underground drain.

Do P traps need to be cleaned?

The experts are Moore Home Services recommend that you clean your P-trap once every 3 months. This is a total of 4 times per year. We also recommend cleaning your drain a few times every year as well.

How do I check my P-trap?

The primary tools for maintenance are a bucket and adjustable pliers. Place the bucket underneath the trap, loosen the nuts at the ends of the P-trap, and remove the trap by sliding it down to release the contents into the bucket. The final step is to check for any blockage in the pipes and then clean them out.

What is the main sewer line trap?

Basically, it's a U-shaped piece of pipe that is installed with the sewer line that runs underground from the home to the municipal sewage main. The downward bend of the pipes collects a small amount of water, which prevents sewage gases from venturing up through the sewer line and into the home.

What is the difference between a running trap and a P-trap?

Our traps are manufactured using food-grade stainless steel, and are recommended for use with all FoodSafe Catch basins: P-Trap for any vertical/bottom outlet connections, and Running Trap for horizontal/side outlet connections.

How to locate main drain in house?

For indoor main drains, you will likely find the cleanout in a bathroom or utility area. When dealing with a bathroom location, check the floor near the toilet. In this scenario, it might be a pipe protruding from the floor or it might be flush mounted into the floor. These main drains tend to have a threaded plug.

Does homeowners cover sewer line?

In most cases, home insurance will cover sewer line damage from specific events. This includes extreme weather (excluding earthquakes and floods), vandalism, fire, and damage from vehicles or falling objects.

How to unclog main sewer line?

Your step-by-step guide: How to clear a main sewer line clog
  1. Step 1: Loosen the cap on the drain pipe. ...
  2. Step 2: Open the cap and let the buildup drain out. ...
  3. Step 3: Feed the auger cable into the drain pipe. ...
  4. Step 4: Run the auger until the clog is clear—and beyond. ...
  5. Step 5: Hose down the pipe and auger cable.

Where is the P-trap located?

The P-trap is the P-shaped section of pipe in the line that runs from the bottom of your sink to the wall. It's shaped this way to trap sewer gasses and prevent them from coming out the sink as well as to catch debris that's been washed down the sink, such as hair or food scraps.

How do I find my sewer trap?

The easiest way to locate the sewer cleanout is to walk backward from the main sewer line (nearest maintenance hole or a curb with a large S stamped into the concrete) or your home's septic system. Follow the line from there; it's usually located next to the house in line with the septic tank or municipal sewer system.

What happens if your house doesn't have a sewer cleanout?

If your main sewer line is clogged and you don't have a cleanout, you may be able to clear the blockage using a plunger or a plumber's snake. You have a few options to try before calling a professional.

What does a clogged P-trap smell like?

This process will give off a foul-smelling hydrogen sulfide gas, which smells like sewage or rotten eggs. Also, mold grows where it's warm and wet — and mold growth on the debris causing a drain clog can also cause a bad smell.

What does a shower P-trap look like?

The Different Parts of Your Shower Drain's P-Trap

Although they look like the curved pipes under your sink, they are quite different in that they have a greater curve. Your shower's P-trap consists of three main parts: the inlet, water barrier, and outlet.

Should there always be water in the P-trap?

Plumbing traps, commonly called P-traps, are an important part of your plumbing system. They are designed to constantly hold water in the drain to prevent sewer gas from escaping into the house. While sewer gases may contain noxious odors and smell terrible, they can also be explosive and poisonous.

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