Skip to Content

Where is the Kitchen Sink Trap? (Explained)

If your kitchen and your entire home smell funny all of a sudden, and the water in your sink is not flowing down the drain, it’s time to check the kitchen sink trap. But where do you look for it?

The kitchen sink trap and is one of the most significant parts of your sink draining system. It keeps toxic gases out of your homes and makes sure your plumber doesn’t make rounds every month.

Where is the kitchen sink trap located?

The kitchen sink trap is located under the sink. If you look under your kitchen sink, you will see a U-shaped pipe connected from the drain of the sink to the wall. The trap under the sink collects debris while preventing sewer gasses to enter the kitchen.

There are a few different types of traps that can be found. These include P, Q, or S trap which are popular. Other ones include drum trap, bottle trap, running trap, or grease trap.

In most kitchens, a P trap is used. Although the shape of the trap is U-shaped, viewing it by tilting one’s head makes the whole drain system looks like a P. Hence it is regularly known as a P system.

How do you find a sink trap?

To find a sink trap, open the cabinet under your kitchen sink and look under the sink. You will find a pipe that looks like a P if you tilt your head. Moreover, if you have any open drain in your house, whether it is a bathroom drain or a sink drain, you will find a trap.

What does a kitchen sink trap look like?

Although sink traps are commonly known as P traps, the trap is a U-shaped one. The U-shaped trap is connected to the tailpiece of the drain system. The tailpiece is locked in with the strainer body, gasket, and washer.

The sink trap curves to a U shape before horizontally connecting to the wall again. Sometimes pipe following the trap may be connected to the floor. Right at the bottom of the trap, there is a cleanout sink plug that can be opened or closed.

What is the standard size of a kitchen sink trap?

The standard size of a kitchen sink trap is 1.5 inches in diameter length.

What does a sink trap do?

The curved part of the pipe is the sink trap where a small amount of water is always deposited. The water acts as a seal to the passage. If sewer gasses travel through the pipe, this water-filled trap prevents the harmful gasses from entering your home.

When used water passes through the pipe, the solid particles get stuck in the trap. When you use the tap next time, water again flows from the drain opening to the trap and through to the wastewater drain.

Does a kitchen sink need a trap?

Yes, a kitchen sink needs a trap for several reasons. The primary purpose of having a trap under the sink is to stop sewer gasses from entering your home.

Nobody wants their homes to smell bad. If the retained water in the trap does not seal the area, and sewer gasses will infiltrate the kitchen, as well as your entire home.

You may think bad-smelling gasses can’t be that dangerous. True, small exposure won’t be lethal. However, you must know that the main component of these gases is hydrogen sulfide and ammonia.

Prolonged exposure to such toxic gasses can be dangerous for your health if you inhale them. These gasses are poisonous and have the properties to blow up as well.

Another reason your kitchen sink might need a trap is to keep the main drain system free of clog. The trap stops bigger sold food particles from entering or clogging the rest of the system. The cleanout trap can be opened at any time to clean the trap.

Traps under your sink drain can also save your valuable ring from flowing away. If you drop something small inside the drain, such as a ring, you can get it out as it gets trapped in the U-shaped pipe.

Does every P trap need a vent?

A vent in any plumping system controls the airflow in the P trap, as well as the whole drain system. Whether it is a bathroom sink or your kitchen sink, all P traps need a working vent.

A vent blocks the water in the P trap from being sucked out. The venting system in the P trap keeps the airflow regulated by creating a forward air pressure in the drain.

If there is no vent, negative air pressure will suck out all the water that acts as a seal. This would mean poisonous sewer gasses can enter the kitchen without hindrance.  

A P trap without a vent will not serve its purpose, and the entire plumbing system will fail to function accordingly. 

How to clean kitchen sink trap?

You will need the following:

  • A bucket
  • A toothbrush or any cleaning brush
  • Towels
  • Wrench
  1. Place the bucket under the trap. This will collect any water that drops from the trap when you unscrew it
  2. Detach the joints. Using the wrench, loosen the nuts of the U-shaped trap. Unscrew the joints on both sides of the trap. Remove the pipe you unscrewed completely
  3. Clean the trap using a brush and water. Use the brush to remove dense dirt, and rinse it with water until fully cleaned
  4. Put the trap back in place. Use the wrench again to lock the split joint nuts in with the trap.
  5. Test the drain system. Run the tap water a few times and test if you have screwed the trap properly. Remove the bucket and clean the area under the sink.

How do you tell if P trap is clogged?

There are a few ways to understand whether your P trap is clogged and needs cleaning. One of the first signals is when water does not pass through the drain opening immediately.

You notice that water will get trapped in the sink. Another way of telling if your P trap is clogged is when water flows back to the sinks.

While the water flows down, the strainers in the sink might slow down significantly; sometimes the bad odor can be taken for clogged P trap. This smell is from sewer gasses and can be perilous to your health.

Sometimes, too much clogging on the P trap can cause leaks from the pipe.

How do you unclog a P trap sink?

There are a few simple ways to unclog a P trap sink.

Baking soda and vinegar

Mix one-third cup of baking soda and one-third cup of vinegar. Pour this mixture into the drain hole and wait for 30 minutes to one hour. After that, pour in hot water.

The mixture of baking soda and vinegar produces a fizzing effect. This is a natural method of unclogging traps and has been used for years.

Boiling water

If you don’t have baking soda at home, another natural and effective method of unclogging P traps is pouring boiling hot water in the sink. Make sure the water is boiling when you pour it. If the gunk is not too hard, boiling water could melt the debris and clear the passage.

Baking soda and salt

Mix equal parts of baking soda or bicarbonate soda and salt. The most effective amount is a half cup of each. Pour the mixture and wait for at least 20 minutes before pouring in hot boiling water.

You may hear fizzing sounds from the reaction. This established, natural method helps melt away new gunk in the trap.

Manual cleaning of the trap

For this, you will need to detach the trap from the drain system to clean it. At first, unscrew the slip joint nuts and detach the trap.

Use a brush and water to clean all the clog and gunk from the trap. Fix the trap back to the pipe. At last, run a test by turning on the tap a few times to check if there is any leak.

How much does it cost to replace a sink trap?

The installation cost of a sink trap is much lower than its replacement cost. The cost of replacing a sink trap can be high, depending on a number of factors.

For material, it will cost you $90 to $120 dollars depending on the material of the trap. If you are not keen on replacing your sink trap by yourself, you will have to hire a plumber or sewer cleaner. The additional installation costs would be $40 to $150 dollars.

On average, the total cost of replacing a sink trap would be in the range of $250 to $350 dollars.

How to replace kitchen sink trap?

If the water in your kitchen sink is back flowing or drowning away too slow, you know you have a problem with the sink trap. While small clogging or smelling issues can be solved by clearing out the trap, few issues need a replacement.

Your kitchen sink trap would need replacement if it, for some reason, gets corroded or permanently trapped. To replace your kitchen sink trap, you can check products like EasyDrain Ref. 510 Expandable & Flexible 1-1/2″ P-trap, Snappy Trap 1 1/2″ Drain Kit for Single Kitchen Sinks or for Double Bowl Kitchen Sinks on Amazon.

Replacing a kitchen sink trap can cost you a few hundred dollars. If you are not so keen on spending that money, you may follow these easy steps to replace your kitchen sink trap.

  1. Gather the following components: Slip Joint Pliers, Towels, Nuts, Bucket, Plumber’s Putty, Pipe lubricant, or wrench
  2. Put the bucket underneath the trap.
  3. Unscrew each of the joint nuts at the ends. You will have to use a wrench or pliers to loosen the slip joints if they are too tight.
  4. Loosely fix the new tailpiece to the bottom of the sink strainer.
  5. If you have two basins in your sink, you will need a T fitting. You can use pipe lubricants to attach the T system for firmer attachment.
  6. Join the trap arm and then connect the trap bend to the trap arm.
  7. Use the plier or wrench to tighten the nuts again
  8. Check if the nuts are too tight. Do not over-tighten the nuts. If you do, the trap might crack at any end.
  9. Turn on the tap and run water to check for leaks a few times.

Now, every time you have to replace or clean the kitchen sink trap, you would not have to worry about calling your plumber. You would know the trap is right under your sink.

 In fact, if you follow the simple steps we have mentioned, you can clean or replace a trap all by yourself.