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Drain Smell in House | Causes, Impacts & Solutions




October 29, 2023



Causes of Smelly Drains

Table of Contents

A drain is a primary vessel or channel takes the wastewater to sewers or stormwater mains. It includes the waste fluids from bathrooms, kitchens, or washing areas. An efficient plumbing system helps proper drainage and contains the smell of wastewater flowing through the pipes.

However, any issue with the plumbing system, such as blocked drains or sewer gas leaks, can lead to annoying smells in the home.

Causes of Smelly Drains

Smelly odours are the first indications of a compromised drainage system. That’s why it is vital to identify the sources of the sewer gas leak or the blocked drain to solve the root cause of the smell in the house.

The following are some of the possible causes of smelly drains:

Food Waste

When food leftovers are directly washed out into the drains, it can cause smelly drains and clogged pipes. The incomplete decomposition of food waste inside the drainage pipes can develop nasty odours.

Kitchen Sink

The kitchen sink deals with different waste substances, such as dish soap, food waste, etc., which gets buildup over time. Therefore, a grimy or unclean overflow system can lead to sewer gas odour from the kitchen sink.

Shower Floor Drains

Sewer gases can also lead to drain smell from shower floor drains. It may be due to a buildup of waste materials, including body oils, hair, soaps, shampoos, and other liquids flowing through them. Accumulated waste substances can also lead to the growth of bacteria, causing smell.


U-bend, a sewer gas trap is present under the kitchen sink. It can get dry if you have not run water for a while or you have been away from your house for holidays. Then, it becomes inefficient and cannot stop sewer gases from escaping out of the plughole. Moreover, blockages or leakages in the U-bend can also cause sewer smells.

Tips for Removing Drain Smells from House

Vent Pipe

The vent pipe assists in managing the plumbing system’s pressure and moves odours outside the house. A crack or incorrect installation process can lead to a malfunctioning vent, resulting in sewer gas leakage. Moreover, a bird’s nest, leaves, rust, snowfall, etc can also result in a blockage inside the vent.

Wax Ring

A wax ring is used for sealing the toilet drains, and a faulty wax ring can cause a drain smell in the house.

Impacts of Sewer Gas Smell

Sewer gas is the by-product released during the breakdown of waste substances. It is not only irritating to the senses of smell but is also harmful to health as it contains ammonia, carbon monoxide, esters, hydrogen sulphide, methane, nitrogen oxides, and sulphur dioxide.

Its potential health problems include breathing difficulties, cough, eye irritation, fluid accumulation in the lungs, sore throat, etc. Consistent exposure and higher concentrations of hydrogen sulphide can lead to severe issues, such as dizziness, unconsciousness, pneumonia, etc.

Impacts of Sewer Gas Smell

Tips for Removing Drain Smells from House

Drain smells can get worse with time and are required to be resolved quickly. After identifying the leading cause of drain smell in the house, you need to tackle the issue with these possible measures:

  • Clean or replace the corroded and damaged pipes.
  • Clean the overflow system to remove the smell coming from the kitchen sink.
  • Ensure that your plumbing system is watertight to banish the horrid smells.
  • Ensure the U-bend does not get dry and remains filled with water.
  • Pour bleach into the drains, which acts as a disinfectant to eliminate the bacteria from a drainage system.
  • Pour hot or boiling water into the smelly drains to break up the blockages and dislodge the food or other debris.
  • Repair or replace the deteriorated vent pipe.
  • Replace the damaged wax ring to fix the issue of the sewer gas smell.
  • Sprinkle some baking soda in the plug hole of the troubled drains and add some boiling water to eliminate the odours.
  • Use a cleaner to clean the drain area thoroughly.
  • Use a drain snake to clear foul-smelling and stubborn blockages.

You can follow the above-mentioned steps to solve the issue of drain smell in your house. But in severe cases, you will need to hire a professional expert to resolve this problem effectively. The professional intervention will help in the technical management of the issue, ensuring safety with reliable services.

Regular cleaning and rinsing of drains are efficient strategies to keep your system running smoothly and prevent materials buildup.