
July 28, 2025

Read Time
5
What to Expect in Blocked Drain: Signs, Symptoms, and Solutions
Blocked drains can disrupt your entire day, causing inconvenience and even potential water damage to your property.
Have you noticed slow drainage or strange gurgling sounds coming from your sink or shower?
These might be the early signs of a blocked drain. If ignored, they can escalate into more severe plumbing issues, costing you time and money. Understanding what to expect in blocked drain situations is essential to keeping your plumbing system in good working order.
In this guide, we’ll walk you through the blocked drain symptoms, what causes blocked drains, and how to identify potential issues before they turn into emergencies.
We’ll also share solutions for clearing your drains and preventing future blockages.
Common Signs of a Blocked Drain
Here are the common signs of blocked drains.
1. Slow Drainage
One of the most common blocked drain signs is slow drainage. If you notice water taking longer than usual to drain from your sink, shower, or bathtub, it's likely that there’s a blockage forming somewhere in the plumbing system.
What to do:
- Check if multiple fixtures in your home are affected. If so, the blockage may be in the main sewer line, which can lead to bigger issues if left untreated.
2. Foul Odours from the Drain
Another telltale blocked drain symptom is the presence of foul, unpleasant smells coming from your drains. These odours are caused by trapped food debris, grease, or organic matter that has started to decompose within the pipes.
What to do:
- If you notice a persistent bad smell, it’s a sign that waste is accumulating and may lead to a larger blockage. Address this problem as soon as possible to prevent more severe issues and health risks.
3. Gurgling Sounds
Hearing strange gurgling noises when you use your sinks or flush the toilet could be a sign of a blockage. These sounds happen when air is trapped in the pipes and struggles to escape as water flows past the obstruction.
What to do:
- If you hear gurgling noises, it’s a clear indication that something is blocking the water flow. This could lead to backflow or more serious issues, so it’s important to address it promptly.
4. Raised Water Levels
When water levels rise higher than usual in your toilet or sink, particularly after flushing or draining, it’s a sign that something is obstructing the drain.
What to do:
- This may be a serious blockage. If left unresolved, raised water levels could lead to overflows and cause water damage to your home.
5. Backflow
Backflow occurs when water or sewage flows back into your sinks, showers, or toilets. This is a more severe sign of a blocked drain and requires immediate attention.
What to do:
- Backflow is dangerous and unsanitary. If you experience it, call a professional plumber immediately to avoid further damage to your plumbing system.
6. Lower Water Levels in Toilets
A blocked drain can also affect the water levels in your toilet. If the water level is unusually low or rises and drains away slowly when flushed, it's a clear sign that something is obstructing the pipes.
What to do:
- Check for other signs like slow drainage and bad smells, and get a professional to inspect the situation before it worsens.
What Causes Blocked Drains?
Understanding the common what causes blocked drains will help you prevent the problem from occurring in the future. Below are some of the most frequent causes of blocked drains:
1. Accumulation of Grease, Hair, and Soap Scum
In bathrooms and kitchens, hair, soap scum, and grease are commonly washed down the drain. Over time, these materials accumulate and form a thick sludge that obstructs the flow of water.
2. Foreign Objects
Sometimes, non-flushable items like wipes, sanitary products, or cotton balls are mistakenly flushed down the toilet, leading to blockages in the pipes.
3. Tree Roots
In some cases, tree roots can grow into your plumbing system, particularly in outdoor or underground pipes. This can cause severe blockages that may require professional attention to fix.
4. Mineral Buildup
In areas with hard water, mineral deposits can build up inside your pipes, narrowing the flow of water and eventually causing a blockage.
Health Risks Associated with Blocked Drains
Blocked drains are not only inconvenient, but they can also pose serious health risks if not addressed promptly.
- Bacterial Growth: Stagnant water in blocked drains can harbour harmful bacteria like E. coli, Salmonella, and others, potentially causing stomach issues, fever, and vomiting.
- Foul Odours: Decomposing food or waste trapped in your pipes can create unpleasant smells, which can lead to headaches, fatigue, and stress.
- Toxic Gas: In severe cases, gases like methane or hydrogen sulphide can accumulate in blocked drains, creating a hazardous environment for your home.
Solutions for Clearing Blocked Drains
If you notice any of the symptoms mentioned, it's essential to act quickly before the issue escalates. Below are some common solutions for dealing with blocked drain symptoms:
DIY Solutions for Minor Blockages
Here are the DIY solutions for minor blockages
1. Boiling Water
Boiling water is an effective way to break down grease and minor blockages. Simply pour it down the drain and let the heat dissolve the obstruction.
2. Baking Soda and Vinegar
A simple, eco-friendly solution involves combining baking soda and vinegar to create a fizzing reaction that can help break up blockages in your pipes.
3. Plunger
For minor blockages in sinks or toilets, a plunger can often do the trick by creating a vacuum that loosens the blockage.
4. Drain Snake
A drain snake is a useful tool for removing deeper blockages that cannot be dislodged by boiling water or a plunger.
5. Soda Crystals or Washing Powder
For stubborn blockages, pour soda crystals or washing powder mixed with hot water down the drain to help clear the obstruction.
Professional Help for Severe Blockages
For more severe blockages or when multiple fixtures are affected, it's best to call a professional plumber. Here are some advanced solutions:
1. Hydro Jetting
This method uses high-pressure water to clear debris and blockages from the pipes, ensuring thorough cleaning without damaging the system.
2. CCTV Drain Inspections
A CCTV drain inspection can accurately diagnose the location and nature of the blockage, allowing for precise and effective clearing.
Preventing Blocked Drains
While some blockages are inevitable, there are steps you can take to prevent them from happening in the first place:
1. Avoid Pouring Grease or Oil Down the Drain
Grease can solidify in your pipes, leading to blockages. Always dispose of grease in the trash.
2. Use Drain Strainers
Install strainers in your kitchen and bathroom drains to catch hair, food particles, and soap scum before they go down the drain.
3. Don’t Flush Non-Flushable Items
Avoid flushing items like wipes, sanitary products, and cotton balls down the toilet.
4. Regular Drain Maintenance
Clean your drains with hot water regularly and use mild cleaning solutions to keep them clear of debris.
What to Do If Your Drain Is Blocked
If you've noticed any of the signs of a blocked drain or suspect an issue, it's best to call a professional plumber.
At Sewer Surgeon, we specialise in fast, efficient, and reliable drain clearing services. Our expert team uses advanced tools like hydro-jetting and CCTV inspections to tackle even the toughest blockages.
For fast, affordable, and reliable drain solutions, contact Sewer Surgeon at 1300 734 677.
FAQs
What is the best solution to unblock drains?
For minor blockages, try boiling water, baking soda and vinegar, or using a plunger. For more serious blockages, it’s best to call a professional plumber.
Can a drain blockage clear itself?
Sometimes, minor blockages may clear themselves over time, but it’s risky to wait. Ignoring the problem could lead to more severe issues, including pipe damage and water backups.
How to solve blocked drainage?
You can solve blocked drainage with DIY methods such as plunging or using a drain snake. However, if the blockage persists, it’s best to consult a professional plumber for a thorough inspection and clearing.
What causes blocked drains?
Common causes of blocked drains include the accumulation of grease, food particles, hair, tree roots, and non-flushable items.
How can I prevent blocked drains?
Prevent blockages by regularly cleaning your drains, using strainers to catch debris, and avoiding the disposal of grease and non-flushable items down the drain.

Andy Quinn
Founder
Andy Quinn is the founder of Sewer Surgeon, a family-owned plumbing business serving Sydney with over 63 years of combined industry expertise. Andy and his team specialize in delivering reliable solutions for everything from blocked drains to emergency plumbing, ensuring quality service and customer satisfaction.