Washing Machine Smells Like Sewage: Reasons & Solutions

Understanding the Basic Pipework of Washing Machine

Before heading towards the core reasons, let’s have a short overview of the key plumbing gear of a standard washing machine to get a clear picture and understand the reasons.

Drain Pipe: A flexible hose that connects the washing machine with the sewage plumbing pipes to channel the dirty water from the machine to the main sewage system.
P-Trap: A U-shaped plumbing pipe below the standpipe that ensures the prevention of sewer gases entering and prevailing at home.
Stand Pipe: A vertical pipe that connects the drain pipe and main sewage plumbing pipe via P-trap. It ensures efficient water drainage and prevents overflows, leaks, and backflow.
Vent Pipe: It is located at the back side of the machine and extends towards the roof to ensure air ventilation in the plumbing system, and streamline the wastewater drainage from the machine.

Core Reasons for Foul Smell in the Washing Machine

Now, let’s dive directly into the reasons for the foul smell coming from your washing machine.

Plumbing & Drainage Issues

One of the most common reasons for sewage smell is due to issues in the drainage and plumbing system that cause stagnant water, backflow, or trapped gases. Such issues may cause the washing machine to smell like sewage. These situations may come to the surface due to numerous reasons, as explained below:

Failing P-Trap: Due to improper installation or wear and tear over time, the water barrier can evaporate, which may trap the sewer gases, causing a foul smell.
Jammed Drain Pipe: A clogged drain pipe (due to debris or detergent build-up) leads to stationary water, causing a nasty odour.
Clogged Vent Pipe: Obstructed vent pipes disrupt smooth water flow and cause backflow of dirty water which roots a sewage-like smell.

Too Much Detergent or Fabric Softener

Many individuals believe that adding extra detergent or fabric softeners will yield brighter results. However, did you know this practice can actually result in a sewage-like odour in your laundry room? Indeed, using excessive cleaning agents or insufficient water during washing can cause detergent and fabric softener residues to accumulate over time. This not only produces unpleasant smells but also fosters bacterial growth, worsening the issue further.

Lack of Machine Maintenance

Frequently cleaning your washing machine is obligatory to ensure its optimal functioning. According to experts, one should clean the washing machine once a month or after every 30 washes. If not done periodically, the trapped insects, dirt build-ups, or currency notes may lead to a sewage-like smell.

Bacteria Buildup

Bacterial proliferation may occur due to a lack of machine cleaning, detergent or residue accumulation, and stationary water. These bacterial colonies produce hydrogen sulphide gas that causes a sour or sewage-like odour. It is especially the primary reason for sewage smell in laundry rooms with low temperatures and damp environments, as that can expedite the outburst of bacteria.

Incorrect Installations

Another reason could be a faulty washing machine or plumbing installation. Though the machine appears to work properly, it is prone to errors and drain clogs, resulting in a sewage-like odour.

How to Treat Machine Smelling Like Sewage?

There are multiple solutions to solve this issue. Here we have mentioned some of the most effective solutions to treat sewage-like smell from your washing machine:

Service washing: Sometimes, the foul smell is due to damp clothes. Remove all clothing and run a service cycle at a high temperature. This will not only remove the odour but also help kill any bacteria present.

Clean the seal: The seal of your washing machine, located near the door, can become a breeding ground for mould, bacteria, and residue buildup. Regularly cleaning the seal helps prevent odours and long-term damage.

Wash the detergent drawer & filter: Regularly scrub and clean the detergent drawers and machine filters to prevent buildup. Additionally, leave the drawers and machine door open for better air ventilation.

DIY cleaning: Use a solution of distilled white vinegar and hot water to eliminate odours caused by hard water. Adding baking soda can also help remove hard water deposits.

Call the experts: If these tips don’t resolve the issue and the smell persists, it could be a plumbing problem or faulty parts. Contact professionals like Fast Drains to thoroughly inspect the pipework and identify any faults for immediate repair.