10 most commonly asked blocked drain questions answered!

The most common blocked drain questions in Sydney… answered

As leading experts in the field of blocked drains, our plumbers are regularly asked about the cause of blocked drains, how to fix them and how much drain repairs cost. The answer to these questions is not clear cut, because every blocked drain is different, so the below answers should be used as a guide only. We always recommend getting in touch with a professional drainage plumber if your drains are not functioning correctly.

1. Why do my drains smell?

Smelly drains means there is a blockage located somewhere in the pipes. When debris gets caught in the pipes - such as hair, wet-wipes, food scraps and oil - bacteria can grow causing a foul smell. If the smell is only coming from one drain, it’s probably a local blockage meaning the clog is located very close to the plumbing fixture that’s blocking up. For example, a smelly shower drain could be the result of a hair blockage in the floor waste. If multiple drains within your home are releasing a sewer-like smell, the blockage is most likely in the main sewer line and we recommend calling a professional drainage plumber as soon as possible 1800 225 552.

Click here for tips on fixing smelly drains.

2. Why do my drains gurgle?

Gurgling drains are the result of a partial blockage somewhere inside the drain pipes. An obstruction in the pipes will cause the water to drain slowly. This creates air bubbles inside the main drain and that's the gurgle you hear. When you hear gurgling noises it’s best to get a professional plumber to assess and repair the blockage before the pipes becomes completely blocked. If you ignore it and the main sewer pipe becomes completely blocked raw, untreated sewage travelling back up the pipes and overflowing from drains throughout your home.

3. Why is my sink draining slowly?

A slow draining sink in the bathroom, laundry or kitchen is another indicator of a clog forming in the pipes. When the pipe is partially blocked, the water cannot flow freely through the pipes, causing your sink to drain slowly. In the bathroom and laundry, the most common causes are lint, hair and soap scum. In the kitchen, a slow draining sink is normally the result of oil buildup and food scraps that are lodged in the pipes. Simple clogs in the sink are easy to fix using a plunger. You can also try pouring boiling water down the kitchen sink which can help dislodge blockages caused by grease and oil.

4. How do you fix a sink that won't drain?

There are a couple of methods to unblock a clogged sink. First, you can try pouring bicarb soda and vinegar down the sink. When combined, bicarb soda and vinegar fizzle and expand, creating pressure within the drainpipe that can work to dislodge a minor blockage. Another DIY method is plunging. Completely cover the drain opening with the plunger and ensure the seal is tight. Push down with quick forceful movements. This will push pressurised air down the drain, dislodging the blockage.

Click here for more tips on unblocking clogged sinks.

5. Can you flush wet-wipes down the toilet?

The short answer is no. Wet-wipes are one of the biggest causes of blocked drains, costing households and Sydney Water millions of dollars in drain repairs each year. Even wet-wipes that claim to be “flushable” can cause major blocked drains. Wet-wipes are much more durable than toilet paper and do not break down easily in water. They combine with grease and oil that gets washed down the kitchen sink and form large blockages within the sewer pipes. Always place wet-wipes in a bin to prevent blocked drains in your home or business.

Click here for more information on flushing wet-wipes.

6. How to unblock a toilet?

Local clogs located within the s-bend of your toilet can be easily fixed using a flange plunger. Make sure you buy a flange plunger - made specifically for unblocking toilets - as opposed to a cup plunger that is designed for blocked sinks. If the toilet bowl is full of water use a bucket to remove as much water as you can. Completely cover the toilet drain with the plunger and push up and down with forceful movements. We generally do not recommend using drain chemicals because they can damage the pipes.

Click here for more info on unclogging blocked toilets.


7. Why is there water pooling in the bottom of the shower?

Pooling water in the bottom of your shower is generally evidence of a drain blockage that is restricting the water from draining easily. The most common causes of shower drain clogs is hair, soap scum and lint/dust. Hair in particular can build up inside the pipe. To remove the hair, simply take of the drain grate and remove the clog by hand (using gloves). If the clog is too deep to reach, try using a metal coat hanger.

Want more information of blocked or slow draining showers? Click here.

8. How much does it cost to fix a blocked drain?

Depending on the extent of the blockage and impact of any damage, there are a number of blocked drain solutions available. A licensed plumber specialising in drainage work is usually best placed to advise which option is best for you. The below is a general guide for what you can expect to pay for various blockages:

  • $120-$200 for a simple plunge job fixing a local blockage in the toilet or sink

  • $300-$500 to clear a short section of blocked pipe using machines - including hydro jetting and drain camera inspection

  • $500-$3,000 to replace a small section of drainage pipes due to structural damage

  • $5,000-$20,000 to have the entire stormwater or sewer system excavated and replaced with a brand new system.

To see a more detailed breakdown of these drain repairs click here.


9. How much does it cost to fix a blocked toilet?

There is no one-size-fits-all solution to a blocked toilet as it depends on the nature and location of the blockage. As a general guide, you can expect to pay between $120-$250 to get a local-clog removed from the toilet. Local clogs can be fixed with a plunger. If the blocked toilet is caused by an issue further down the line, such as a clog in the main sewer pipes the plumber will need to use special tools such as a jet-blaster. A ballpark figure for water jetting is $350 for the first hour, and $100 per hour after that.

For a more comprehensive look at pricing click here.

10. How does a CCTV drain inspection work?

CCTV drain inspection cameras (aka sewer cameras) are used by plumbers to inspect the inside of drains pipes, both within the home and outside of the home. The camera is fed into a drain access point and transmits real-time video footage back to a monitor operated by the plumber. Plumbers can identify defects in the pipes, determine the cause of blocked drains and recommend accurate solutions for drain problems in an affordable, non-invasive way.

For more information on our pipe inspection services click here.