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Why Does My Drain Smell Like Sewage? (Answered)

Sewage smell from the drain is very irritating and can also have health risks and the chance of accidents. So, you should fix the weird smell from your house drain as soon as possible.

Some issues can be easy to set, but some may need professional attention. This article will explain why drains smell like sewage and what you can do to fix it.

Drain smell like sewage

Bacteria or mold infestation in the drain line can cause a smell like sewage in Your drain. The bathroom or toilet has a p-trap. A sewage-like smell can also appear if your p-trap is dry. A dirty and cloggy drain is a great place for microorganisms. They make different gas and biofilm causing bad smells.

What can be more unpleasant than showering in a bathroom that has a sewage-like smell? Or cooking in a kitchen that has a bad smell?

Yes, we know the issues. So, if you came here to get some information, start investigating the smell, and possibly find ways to fix that, you are in the right place.

Drain pipes usually do not cause any smells, and the drains are designed smartly so that nothing can come from the drain. Still, if you are getting a sewage smell, it indicates there must be something wrong.

Luckily, you can fix most of the smelling issues of drains with a little afford and most household items. But in some complected cases, you will need the help of professionals.

Let’s start with an introductory discussion. Then we will discuss every problem separately. Smells in the drain can show heavy bacteria or mold infestation in your pipe. They produce different gas and biochemicals. The gas and chemicals produce a sewage-like smell.

But how do bacteria live in a pipe? When some organic matter goes through the line, some part of that can stick with the tube. Day by day, the layer becomes thick, making a suitable environment for the bacteria.

They get regular water and food from the dirty water that goes through your pipe. You may notice some slippery things in old nasty pipes. Those are the biofilm the bacteria make to protect them and their habitats from other bacteria.

To stop the bad smell from reaching your house, there are p-traps in your drainpipe. A p trap is a U-shaped pipe that always carries some water in the line. The pipe stops the gases and smells from coming out of the pipe.

If the U pipe leaks or the water is dry, you can get a sewage-like smell from the drain. Brakhage of line and water blockage in the drain line can cause issues like this.

When you find a sewage-like smell, you should take care of the issue as soon as possible as those issues have several risk factors. Sewage can release some poisonous gas that can make you sick.

Sewage bacteria can also produce highly flammable methane and cause fire accidents. But don’t worry, we will explain how to fix it or when to get help from professionals.

Now, let’s discuss the different drain smell issue and their causes.

Shower drain

Sewage smell in shower smell is less typical than in others. But it can still happen. There are also easy ways to clean and fix the sewage smells from a shower drain. We will discuss them in the solution section. Here are the reasons why shower drains can smell like sewage.

Dirty drain:

The shower drain transports dirty water with skin cells, hair, etc. Those can sit on the shower drain and cause a sewage smell. Bacterias grow in those dirty layers and emit foul gases.

This causes sewage smells in the shower drain. Pouring hot water inside the drain can sometimes reduce the smell.

P-trap leakage:

A p trap is an u-shaped pipe that traps some water inside the pipe, so bad smells or disease agents can not come out from the drain.

It also stops the cockroaches and insects from making a home in the gutter. A leak in the p-trap can cause a sewage-like smell in the shower drain.

Washer drain

When you find a sewage-like smell in your home, you will go to your bathroom first to find the source of the bad smell. But smells can come from places we don’t think can cause those issues. Such as a washing machine or dishwasher.

The washing machine and dishwasher drain pipe can also cause bad smells. Here are the common reasons.

Water is trapped in some parts:

Water can get trapped in some parts of the washing machine, which can cause a bacterial infestation in the water, causing a sewage-like smell. Cleaning the lousy water can fix the issue.

Drain pipe:

Dirt and food particles can get stuck in the drain pipe and cause a bacterial infestation. The bacterias produce gas and chemicals, causing sewage-like smells.

Floor drain

Anything that gets a constant moisture source can cause a sewage-like smell. Here is why floor drains can smell bad.

Mold infection:

Molds can grow in moist pipes and have muddy smells. You can remove the pipe cover and spray mold remover to get rid of the molds.

Bacterial infection:

Like other drains, floor drains can smell like swage when dirt sit on the pipe and bacterias grow on them.

Outside drain

Drains on the outside can cause bad smells for those reasons.

The drain needs maintenance:

Every drains need maintenance for proper working, and dirty drains can cause sewage-like smells. You can call plumbers to clean and solve the issue.

Decomposing animal:

If an animal falls and starts to decompose in the drain, that will cause unbearable smells. Remove the animal and bury it to fix the issue.

Kitchen drain

Here are the reasons that can cause sewage-like smells from your kitchen drain.

Bacterial infestation:

Kitchen drains are prone to become infested by bacterial infestation as food parts go through the drain.


A broken p-trap can cause a sewage-like smell from your kitchen drain.

Can you pour bleach down a smelly drain?

Bleach is not suitable for pouring down the smelly drain, especially when you don’t know what’s inside the drain. Bleach has cleaning power but using bleach on a smelly drain can be dangerous.

Bleach is hazardous as it can produce other toxic chemicals or gas when mixed with the chemicals inside the drain. Keep reading to learn the safe way to clean a smelly drain.

How do you get rid of sewer smell in the drain?

Most of the time, cleaning the drain can fix the sewage-like smell issue. Here is the step-by-step process of removing the smell in the drain.

  • Pour boiling water into the drain. The hot water will remove the smell causing bacteria from the drain. Handle the hot water carefully.
  • Remove the lid of the drain with a screwdriver.
  • Add one cup of vinegar and one cup of baking soda to the drain.
  • Wait 5 minutes. And then take a drain brush and scrub the drain.
  • Again, pour hot water to clean the drain thoroughly.

How do I prevent my drain to smell like sewage?

Preventing is always better than the cure. Here are some tips to avoid the sewage smell issues in your house drains.

  • Call a professional plumbing company to maintain and fix the potential issues at least once a year. They will use advanced methods to audit the health of all your sewage lines.
  • Don’t drop the hard object in your drain to make sure the drain does not get blocked.
  • If you do not use a drain that much, you can pour some water into the drain to fill the P-trap. When the p-trap is dry, the smells of the drain can come out from the drain.
  • You can pour hot water once or twice a month to stop the access growth of bacteria in the drains.
  • You can occasionally pour vinegar into the drain to clean the drain.
  • Do not light a fire near the drain when it smells like sewage. Drains can release methane gas.

Final Thoughts

Bacterial infestation can cause drains to smell like sewage. Bacteria’s can release methane, sulfur, and other chemicals that cause the smell. A dry or broken p-trap can also cause a sewage smell. Hot water, vinegar, and baking soda can fix the sewage smell from the drain.