Why Do My Drains Smell Awful?

Smelly Drains

Imagine a perfect house with a furnished floor, big garden, beautiful interior, and a drain that smells like a dead cat. Believe me, it’s not very pleasant to walk around in the house while holding your noses.

Smelly drainage can be a big discomfort for the inhabitants and really kill the impression of your house. If it makes you feel any better, know that you are not alone and a smelly drain is a very common problem. There can be various reasons for the unpleasant odour like a clog in the sewer line, a dead animal, or something more serious like a sewer gas leakage.

Let’s explore each possibility one by one so you can figure out what’s making your drain smell like rotten eggs.

  • Food particles blocking the drain

If your drain specifically smells like rotten eggs, it’s very likely due to the food particles clogged in the drain. Often doing dishes, we empty the plates in the kitchen sink thinking the debris will simply wash away through the drain. However, while draining down, some of the food particles stick to the sides of the pipeline and continue sitting there until they start to rot. The decomposition of the food scraps results in foul odours such as rotten eggs. A smart way of preventing this is to keep running the tap for a minute or two after doing dishes so that the debris may wash away.

  • Missing or dry drain trap

A plumbing drain trap or p-trap is the curved part of the pipe installed under the sink or drain. Its basic purpose is to prevent the escape of sewer gas out of the drain and into the house. The p-trap is always filled with some portion of water that blocks the foul air and smell from escaping out through the drain. Thus, if your drainage system is missing a p-trap or it is not installed properly. The gases will leak out through the sink and cause a foul smell.

Another related problem that often arises is p-trap becomes dry; meaning the water that should’ve been surfaced is not there. This usually happens when a trap is not used for quite some time and the water evaporates. Simply run the tap and pour some water to fill it again.

  • Clogged pipes

One simple reason for the awful smell is clogging in the drain. The blockage could be due to the garbage disposal, leftover food particles, dirt, or leaves. Clogging in the drainage is easy to spot as the water might overflow and pour out of the vent. Moreover, the water will go down the sink or vent much slowly and make a gurgling sound. Consequently, you experience an awful smell like rotten eggs down your drain. Therefore, always keep the vent and sewer lines clear of any debris and in case of severe clogging, call a plumber.

  • Bacteria blockage

Bacteria build-up also contributes to a foul odour coming from your drain. Bacteria can accumulate over time in the p-trap for multiple reasons such as clogging in the drain or from food, hair, and dirt particles in the drain. When p-trap is not cleaned of bacteria for some time, it leads to the creation of hydrogen sulfide gas.

Hydrogen sulfide gas then escapes out in your kitchen or house and it might be the reason why your drain smells like rotten eggs. To fix this issue, clean the p-trap of any impurities, pour some quantity of baking soda and vinegar in the drain followed by hot water.

  • Grease

Grease might be another culprit for your smelly drain. Grease or oil is commonly used as a by-product in foods. When disposing of garbage or washing dishes, we often throw the grease or oil down the drain as well. Anyone who has little knowledge of chemistry knows that simple water cannot wash away oil. That’s why we use dishwashing soaps or liquids.

Therefore, it is not recommended to pour down oil or grease in the sink or drain as they get stuck on the walls of the pipe and emit foul odour such as that of rotten egg. Baking soda and boiling water can again solve this issue.

  • Biofilm buildup

Biofilm is another form of bacteria that builds up in bathroom vents and drains. It is a combination of different types of bacteria and organic wastes that not only form a sticky substance in the vent but it is also harmful to our health. Biofilm is a result of different products like soaps, shampoos, and oils combined with our hair and skin cells.

Over time, biofilm adheres to the walls of the vent, forming a colourless and sticky ring around it. As the debris decomposes, it results in a rotten smell from the drain. Regularly cleaning the vents and using a good disinfectant can prevent biofilm buildup in the drain. 

  • Compromised wax ring

A wax ring creates a divide between the drain and your toilet bowl and prevents sewer gases to escape out. However, if for some reason the wax ring is worn out or damaged, the water from the toilet may start leaking that’ll lead to an awful sewer smell in the toilet. In such a case, you may need to repair or replace the wax ring completely.

Another related issue with the toilets is compromised seals that connect the toilet with the drain. A leak in the seal allows sewer gases such as hydrogen sulfide to release out. Note that such sewer gases are not only unpleasant but may also cause nausea, headache, and sometimes vomiting. Thus, it’s necessary to address the source of the problem at the earliest.

  • Final Words

Prevention is better than cure. We are often not wary of what we are dumping in the kitchen sink or garbage disposal. Also, ignoring the timely cleaning of vent and drain pipes can lead to smelly consequences. A good cleaning disinfectant or a home remedy from YouTube can easily fix most of the plumbing issues in your drain. For more demanding issues, hire a plumber as it’s best not to ‘poke your nose’ in the smelly business you know nothing of.

With little care and a cleaning schedule, we can avoid ruining our perfect moments in the house due to the smell of rotten eggs.