Why does the toilet smell bad even though it's clean?

The household wastewater system has a bend in the road, which helps retain water to prevent odors from rising back up. Because it's curved, it's prone to accumulating dirt and debris, causing odors and blockages.

When a room smells bad, you might immediately think of using fragrances like essential oils or air fresheners to mask the odor, or pouring cleaning products down the toilet. However, once you stop using them, the bathroom may smell bad again.

The structure of the toilet-septic tank system. Photo: RMC.

Therefore, the first thing you need to do is find out where the odor is coming from in order to solve the problem completely. In the bathroom, the toilet and drain are the two places most likely to cause odors. You need to check the following:

- There is a lot of residue buildup in the pipes:Toilets, urinals, and sinks have a siphon pipe that retains water to prevent odors from rising back up. Due to its curved design, this part easily accumulates dirt and debris, causing odors and blockages. To deal with this buildup, use liquid or tablet cleaning products, pour them into the toilet or sink, let it soak for the recommended time, and then flush.

- The septic tank is full:Most homes now use septic tanks, but sludge still accumulates. For households, it's recommended to have your septic tank emptied every 2-3 years. If it's been too long since you last did this, your toilet is likely to smell bad. Many companies now offer this service, charging around 400,000 - 500,000 VND for pumping and transporting one cubic meter of sludge.

- The septic tank's vent pipe is blocked:If not installed correctly, this pipe can become clogged, causing foul-smelling gases to back up. This problem requires a professional plumber to fix.

The siphon pipe is a small but important detail in bathroom design. Photo: RMC.

- The water level in the siphon is too low:Under normal conditions, the water level in the siphon pipe and the toilet bowl should be the same, around 10 cm. If installed incorrectly, the water level in the pipe will be lower, causing foul-smelling gases to backflow and spread throughout the room. In this case, you need to hire a professional to reinstall the toilet correctly.

- The floor drain smells:When installing the drain pipes, you didn't use a siphon, so the foul odor is rising. Additionally, it's possible the plumber mistakenly connected the pipes to the septic tank instead of a separate drainage tank.

After fixing design flaws and emptying the septic tank, you should regularly clean your toilet properly. This includes not only cleaning the interior surfaces but also using pipe and toilet bowl cleaning products periodically.

In addition, families should not flush grease, non-biodegradable waste, regular paper, dirty garbage, or cleaning products not intended for toilets down the toilet.

According to VNE