3 Effective Methods to Clean a P-trap

A P-trap is the U-shaped bend under your kitchen or bathroom sink, which is also found in all of your drains like tubs, showers and washing machines. Cleaning a P-trap is important as it ensures your fixtures drain fast and that there are no bad smells.

The main sign of a clogged P-trap is standing water in the fixture (sink, bathtub, washing machine, shower etc.). A slow draining fixture is another sign that the P-trap is partially clogged, as well as rotten eggs smell coming from the drain.


To clean a P-trap, pour 1 cup of baking soda down the drain followed by another cup of vinegar and after 15 minutes blast boiling water through the drain. Alternatively you can disconnect the P-trap and clean it using a flexible wire brush and warm water.

Since shower, bathtub and washing machine P-traps are not easy to access and disconnect, cleaning them using a combination of baking soda, vinegar and hot water is the best option. You can also pull out the gunk using a hair removal tool (zip-it tool) then flush it with hot water.

To clean a toilet trap, drain the water at the bottom of the bowl then pour a cup of baking soda and 2 cups of vinegar then flush the toilet after 30 minutes. Alternatively, you can clear the P-trap using a toilet auger or flange plunger.

As a minimum, you should clean your P-traps at least once in every 3 months. Cleaning the P-trap prevents the drains from clogging and also prevents horrible smells due to decomposition of organic waste inside the P-trap.

The main reason P-traps smell is because their shape allows them to trap solid organic waste. As the waste starts to decompose, a horrible smell like that of a dead animal or rotten eggs will start coming up through the drains.

Why You Should Clean Your P-trap

cleaning a P-trap

In case you are not aware, the shape and design of a P-trap is usually by design and not by accident. S-traps were experimental and that is why they are currently illegal as I have explained in this post.

Drain traps, as P-traps are also called have 2 main functions:

  • P-traps are and should always be full of water. That water acts as a barrier preventing sewer gases from coming into the house. Instead, sewer gases exit the drainage system through the plumbing vent.
  • They trap solids which would have otherwise clogged the drain line farther away. Unclogging/cleaning a P-trap is way easier than unclogging the drain line.

The disadvantage of a P-trap is that it creates a bit of resistance for the waste and as a result some some waste is trapped inside the P-trap.

The solid waste which is organic in nature will accumulate over time and start to rot/decompose. As you already know, decomposition of organic waste results in an awful smell.

Accumulation of solids in the P-trap also creates a restriction meaning the fixture cannot drain properly. In the beginning, the fixture will be draining slowly but if the problem is not fixed it will be completely clogged, resulting in standing water.

That is why you should periodically clean your P-trap. You don’t need to wait until it is smelly or clogged.

How to Clean a P-trap

There are 3 great methods to clean a P-trap. Let us look at each one of them:

1. Use Baking Soda, Vinegar and Boiling Water


What most folks don’t know is that pouring boiling water down your drains frequently is very effective in cleaning P-traps and the entire drain lines.

Unlike cold water, hot water will melt grease in kitchen sink drains and hair balls in bathroom sink and shower/tub drains.

On the other hand, baking soda and vinegar have been used together for ages to unclog drains. Baking soda being a base and vinegar being a weak acid will react in a fizzing reaction and break down the clog in the process.

Combining baking soda, vinegar and boiling water is every effective. Not only does this method completely clean the P-trap but it also completely removes the bad smell.

This is how to clean a P-trap using baking soda, vinegar and boiling water:

  • Drain standing water. If there is standing water in the fixture whose P-trap you want to clean, start by draining away the water. You want the solution to get straight into the P-trap.
  • Pour 1 cup of baking soda down the drain, slowly followed by another cup of vinegar.
  • Wait for about 15 minutes for the solution to work out its magic.
  • Boil about a gallon or more of water.
  • Pour the hot water down the drain.

While the baking soda and vinegar will break down the gunk inside the P-trap, the hot water will melt it even further and flush it down the drain.

Note: Never use boiling water when cleaning a toilet trap/drain. Sudden expansion of the china caused by the boiling water can cause the bowl to crack. Just use normal hot water from the faucet.

2. Remove and Clean the P-trap

This works very well and easily for bathroom and kitchen sink P-traps. As I have already mentioned, other fixtures like washing machines, showers and bathtubs have P-traps as well but accessing them is not easy.

This is how to remove and clean a sink P-trap:

  • Remove the items under the sink. If you use the area under the sink to store stuff, you will need to start by removing them to give yourself sufficient space to work with.
  • Place a bucket under the P-trap. Since there is already water inside the P-trap, you do not want it spilling on the floor. That is why you need a bucket or pan.
  • Disconnect the P-trap. The connections are usually not that tight so you can use your bare hands to disconnect them. If they are however too tight, use a wrench but gently.

Note: If you carefully look at the P-trap, you will notice that it has a long arm and a short arm. I like to start by disconnecting the short arm. That way, all the water will flow out via gravity.

  • With the P-trap out, try to remove as much gunk as you can with your bare hands. Just know that the contents of the P-trap can be very gross, especially the bathroom sink P-trap
  • Use a flexible wire brush to thoroughly scrub the inside of the P-trap until it is spotless clean. Use warm soap water.
  • Check if the drain line exiting through the wall is dirty as well. You can use a drain snake to clean it.
  • Connect the P-trap back.
  • Turn on the faucet to check if the sink is draining as fast as it should, and to also check if the P-trap is leaking.

3. Clean the P-trap with a Hair Removal Tool

If you want to clean the P-traps of your bathroom sink, shower or bathtub drain, this tool will come in handy.

A hair removal tool, also known as a zip-tool is a plastic and flexible snake with hooks on both sides that is used to pull hair from P-traps. It is cheap, easy to use and unlike other types of snakes it cannot damage your pipes.

Needless to say, bathroom fixtures P-traps are usually clogged by hair. The hair combines with soap scum, shampoo and oils to form a clingy ball that sticks inside the P-trap.

This tool will pull out this hair effortlessly. The only thing you will need to do first is to remove the bathtub stopper or shower drain cover. You don’t have to remove a sink’s stopper but doing so will make your work easier.

Insert the tool inside the drain line, twist it about and then pull it out. Repeat that process as many times as you need to. Again, the contents of the P-trap will gross you out.

When you are done pulling hair out of the P-trap, flush the drain line with hot water.

Wrap Up

And basically that is how to clean a P-trap. To prevent your kitchen sink from clogging, avoid pouring grease down the drain. Check out what to do here.

In the case of a bathtub or shower, installing a hair catcher will ensure that strands of hair will not end up clogging your drains.

Do not also forget to clean your P-traps frequently using baking soda, vinegar and hot water.

I hope you found this guide helpful

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