Sewer Smell From Toilet When Flushed: Causes & Quick Fixes

This article discusses all possible causes of sewage smell emerging from flushed toilets.

Having your toilet or bathroom giving off an awful septic smell when flushed is gross and a clear sign of a problem. This is abnormal and requires urgent attention to address.

Now, many reasons can be given for sewage smell from toilet.

Toilet Smells Like Sewage When Flushed

This article discusses all possible causes of sewage smell emerging from flushed toilets.

Does sewage smell from flushed toilets point to a major problem? Understanding the underlying problems helps you take appropriate actions.

So, without delay, we’ll get into the origins of toilet smells when flushed.

The Type of Smell Matters

At the start of this article, a sewage smell was identified as coming from a flushed toilet.

The aim is to identify the causes. There are several possible causes to a toilet smelling that way and we’ll be discussing such within a short time. Basically, three types of smell could emerge from a toilet.

They include the smell of urine, the smell of sewage as well as rotten egg smell. The first (urine smell) mostly has to do with a broken wax seal or may simply require a clean or proper flush.

Sewage smell after a toilet smell indicates several possible causes. The same applies to rotten egg smell, but our focus will be on sewage smell.

Here is why your toilet smells like rotten eggs when flushed.

Why Toilet Smells Bad After Flushing

Perceiving a sewage smell after flushing your toilet is clearly not a good sign. In other words, it’s not normal and needs to be probed. Whatever the problem is, it could be one of several possible scenarios.

Some of them include infrequent usage of toilets and blockage or clogs.

Other possible causes of a smelly toilet include damaged toilets, clogged sewer vents, cracked toilets, and sewer organisms. For a better understanding of these causes, it will be necessary to discuss each of them.

Let’s begin as follows;

  • Infrequent Usage of Toilet

Holiday homes only see occasional usage. In other words, these are secondary homes only visited or used during holidays or occasionally. Without a caretaker, fixtures such as toilets are likely to malfunction.

One example of a malfunctioning toilet is when the water layer or trap meant to prevent sewer gases escape dries up. A water layer or trap is crucial to a well-functioning sewer system.

With less usage, such water dries up, thus creating an opening through which sewer gases escape.

This problem isn’t restricted to holiday homes. Toilets in your primary home could also be affected. This is most common with toilets in basements which see less usage.

When water evaporates or dries up, it’s common to perceive sewage smells.

This is mostly the case when flushed. However, replenishing the water layer or trap by simply flushing your toilet is enough to stop the smell.

  • Blockage or Clogs

A toilet will readily stink when flushed due to clogs within the plumbing system. Ordinarily, wastewater comprising of both grey and black wastewater should end up in a sewer or sewage system.

However, blockage results when a variety of items end up in the sewer system.

These items are not septic safe and include paper & cotton goods, flushable wipes, hair, coffee grounds, lingering food, sanitary products, feminine hygiene products, and tick toilet papers, etc.

Continued usage of such items is likely to result in clogs.

As they accumulate, blockages result. As these slowly decompose, a sewage smell is given off whenever you flush the toilet. Plus, it drains slowly.

You’ll need to have your drainage pipe inspected by a professional and have the clog gotten rid of as soon as possible.

  • Damaged Toilet

With continued use, a toilet is likely to develop wear and tear.

Here, the most affected part is the wax sealing ring beneath the toilet. This key component serves to hold the toilet in position and also keep sewer gas and smell from escaping.

You may notice a wobbly or rocking toilet. When this is seen, it’s a clear sign that your wax seal is worn off.

Another possible cause why your sealing ring is broken could be the frequent usage of a plunger. The upward suction pressure applied when pulling the plunger could lead to damage to the sealing ring.

The problem is more visible when flushing the toilet. Here, agitation of wastewater within the sewer system leads to escape of sewer smell. This is one problem that can be fixed via DIY maintenance.

However, it’s best to have an experienced plumbing technician check and fix such.

  • Clogged Sewer Vents

Sewer vents are provisions that allow for the escape of sewer gases. So, how does a vent built for gas escape become clogged? Several things could be responsible.

Birds could build their nests within the vents and also, there may be rodent or bird carcasses.

With the usual escape route clogged, sewer gas finds alternative routes which include your toilet. Whenever you flush, these gases find a way to escape.

This could be one of the reasons why your toilet smells whenever you flush.

  • Cracked toilets

Cracks are likely to occur with time due to wear and tear. Eventually, a toilet may give way leading to the escape of sewer gases especially when such cracks are below. When flushed, sewer gases are bound to escape.

Some cracks might be so bad that sewer gases leak continuously even when such toilets aren’t flushed. In all cases, it’s best to have such a toilet replaced.

  • Sewer Organisms

Sewer bacteria may be the reason why your toilet smells. These aren’t visible to the naked eye. However, they could cause visible discolorations within a toilet bowl as they multiply.

The smell given off by such bacterial action could be mistaken for sewer gas leakage.

Here, a thorough cleanup using a disinfectant cleaner could resolve the problem. If it doesn’t, such a problem could extend beyond the presence of sewer organisms.

Your Situation Could Be a Combination of the Above Problems

A smelly toilet when flushed could be due to one or more of the above problems. It’s necessary to have a professional diagnose the problem to fix it.

If you have a slow-flushing toiler, here is a quick fix.

Experiencing a stinking toilet whenever flushed isn’t only uncomfortable but also exposes you to health risks. All of that can be avoided by identifying the root causes and resolving them.

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