Toilet Smells Even After Cleaning? (Possible Causes & Fixes)

Matthew Mountain
by Matthew Mountain

It’s definitely not an enjoyable task but certainly a necessary one, and that’s cleaning a toilet once or twice a week. Routine cleaning will ensure the toilet is sanitary, odor-free, and operating properly.

But sometimes a toilet can emit a foul odor, even after a thorough cleaning. This article explains what can make a clean toilet smell bad, and it also highlights some useful cleaning tips. If you don’t have the means to address the problem on your own, it’s best to get in touch with a professional plumber.

If your toilet looks clean but it’s emitting a foul smell, there could be a problem with the P-trap; the tank could be dirty; the drain is clogged; the wax ring is compromised; there’s sewer bacteria in the bowl; the pipe vent is clogged; the water level in the bowl is low or there’s a crack. A professional plumber will be able to identify what’s causing the smell.

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What Causes a Clean Toilet to Smell Bad

After a thorough cleaning, a toilet shouldn’t smell bad, right? Unfortunately, this isn’t always the case, as several malfunctions can occur and cause this result. Some of these malfunctions are difficult to prevent and/or detect, but that doesn’t mean you’re powerless.

If your clean toilet is smelling bad, then it may be because of one or multiple of the causes described below. Some of these problems can be addressed DIY but the majority of them require professional assistance. There are also some plumbing-related issues that only your local water company can address, and while these are briefly explained later, it’s important to point out that these are uncommon.

P-Trap Malfunction

If there isn’t enough water in your toilet’s P-trap, then a foul sewage-like smell can omit from your toilet. The P-trap is located behind the toilet because it’s part of the pipe. It’s supposed to be filled with water, but sometimes the water filling it can evaporate.

This is a common problem for toilets that aren’t used frequently. If you notice that you’re getting a bad smell from a toilet you don’t use all the time, try flushing several times. Doing this should fill the toilet’s P-trap with water and cause the bad smell to quickly dissipate.

Dirty Tank

Cleaning the toilet bowl thoroughly isn’t enough. You need to clean the tank as well. The toilet tank can absorb the smell of waste and sewerage, especially if it’s not cleaned properly and routinely.

The solution here is a simple one: clean the tank! Cleaning this part of the toilet is no harder than cleaning the bowl.

Just pour some white vinegar inside the tank and then use a toilet brush to scrub the walls. After some thorough brushing, let things sit for awhile and then flush the toilet several times so all the water in the tank is cleared out.

If you do this well, the bad smell should go away and not come back—provided you clean your tank often.

Clogged Drain

The problem with clogged toilet drains is that a clog can be present even when it looks like the toilet is flushing normally. A foul smell coming from a seemingly clean toilet can be caused by an under-the-radar clog.

If you suspect that the clog is coming from the drain, the first thing you should do is grab a plunger and try to remove the clog this way. If this is ineffective, then you should get a drain snake and try to remove the clog this way. Using drain cleaner can also be effective.

But if drain work seems out of your league, there’s always the option of getting help from a professional plumber.

Compromised Wax Ring

A sewer-like smell emanating from the toilet can also be caused by a compromised wax ring. The wax ring sits below the toilet and it acts as a seal. It also keeps the toilet in place while preventing sewer gas and water from escaping.

But a wax seal is not invulnerable, and over time it may get loose and/or wear down. When this happens, the most common result is the emission of a very bad smell, one that’s coming directly from the sewer line beneath the toilet.

Fixing a Wax Ring

Fixing a wax ring DIY is possible, but the majority of individuals shouldn’t do this on their own. Instead, when you’re facing this situation, you should get a professional plumber to help you. They’ll have the tools, know-how, and experience necessary to install one of these properly. Hiring a plumber ensures you don’t have to worry about the smell later on.

You could also get a waxless seal, as these are compatible with most toilets. If your wax ring is compromised, and repair is not possible, then you should ask a professional plumber what they think about waxless vs. traditional wax rings.

Sewer Bacteria

There’s also the chance that live bacteria has migrated from the sewer to your toilet’s bowl. These microorganisms usually cling to the rim of the toilet bowl. They will reproduce and expand in the toilet if they’re left unchecked, and when this happens a foul smell can be the most significant consequence.

If you don’t know that these bacteria are reproducing under the bowl’s rim, then you may think that overlooking this spot of the toilet during cleaning is permissible. Never overlook any spot of the toilet during cleaning, as odor-causing bacteria and particles can lurk in the tiniest nooks and crannies.

Getting rid of these microorganisms is not hard. All you need to do is pour several cups of bleach into the flush valve of your toilet. This component is inside the tank.

After you do this, flush the toilet several times. The bleach that you poured in will come out around the rim and run down the sides of your toilet bowl. This is a great way to get rid of those foul-smelling microorganisms. Just be cautious when using bleach, as this is a toxic substance and you don’t want to go overboard when pouring it.

Clogged Pipe Vent

The vent pipe is an integral part of a home’s plumbing system, and when this gets clogged the smell of sewage is likely to emanate throughout the bathroom. A vent pipe, when working properly, vents sewer gasses while ensuring there’s proper airflow; there needs to be airflow so wastewater can flow freely.

But when the vent becomes clogged, the gas won’t be able to vent through the designated spot, so it backs up until it eventually escapes out into the bathroom. If there’s a foul odor coming from your seemingly clean toilet—and all the aforementioned problems aren’t the cause—then you should check the vent pipe and see if there’s blockage.

Leaves and other natural debris can clog the vent pipe, or it may be that a bird has made the vent pipe their home. In any case, if there’s blockage, calling a professional plumber to handle the situation is a good idea.

Low Water Level

Something as simple as a low water level in the toilet bowl can also cause a sewer-like smell to emit. This is because sewer gas can escape when there’s a low water level in the bowl.

The key here is identifying the cause of the low water level. If a blocked pipe is the cause, this problem alone could cause a foul-smell to emit. Low water could also be caused by something innocuous, e.g. the family dog is drinking out of the toilet bowl because the lid isn’t down.

You should first identify what’s causing the low water level and then address this problem. If you get the water level under control and the smell persists, you’ll know the water level isn’t the issue.

Toilet Crack

A crack in the toilet bowl can also lead to emission of a bad smell. Here again the problem is a low water level. If you notice a leak on the floor under the toilet, it’s quite likely there’s a crack somewhere. It’s best to get a crack handled right away, as cracks can get worse over time and lead to larger leaks and overwhelming odors.

If the crack is minor, then it’s likely a simple and affordable repair is all that’s needed. But if the crack is major, and it generally looks like your toilet is on its last legs, then getting replacement is probably the best option.

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Related Questions

Is rust ring removal possible?

Getting rid of a rust ring isn’t that hard. You can use borax or other standard toilet cleaners to do this. One unique method is using Coca-Cola to remove the rust ring. You’ll be amazed at how well this stuff breaks down rust.

What if the toilet smells like urine?

When the toilet smells like urine, even though it looks clean, it may be because the smell is coming from the tank. If you lift the lid of the tank and the smell hits you like a ton of bricks, you’ll know you’ve found the source. Just clean out the tank with vinegar or disinfectant and then flush repeatedly.

Matthew Mountain
Matthew Mountain

Matt loves everything DIY. He has been learning and practicing different trades since he was a kid, and he's often the first one called when a friend or family member needs a helping hand at home. Matt loves to work with wood and stone, and landscaping is by far his most favorite pastime.

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