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That Drip, Drip, Drip: Your Guide to Fixing a Leaking Toilet

How to Identify and Fix a Leaking Toilet

There’s nothing more distracting than a persistent dripping sound when you’re trying to sleep. That small but constant “drip, drip, drip” is not just an annoyance; it’s the sound of your money and precious water going straight down the drain.

A leaking toilet is one of the most common plumbing issues we see in households. It usually starts when the toilet is nearing the end of its lifespan or when parts inside the cistern (the tank) begin to fail.

While a few drops might seem trivial, the impact adds up quickly. A continuously running toilet can waste around 760 litres of water a day—that’s more than 50 times the amount used for a single flush. This is why it’s so important to identify and fix these small leaks early.


Toilet Cistern Colour Leak Test

🛠 How to Tackle a Leaking Toilet


So, how can you tell for sure if your toilet is leaking? Before you start taking things apart, here’s a simple and highly effective trick that professionals use.


💡 The Plumber’s Tip: The Food Colouring Test
  • Step 1: Add Colour – Carefully lift the lid off your toilet cistern and add a few drops of food colouring to the water inside the tank. Dark colours like blue, red, or green work best.
  • Step 2: Wait – Put the lid back on and do not flush the toilet. Leave it for about 20-30 minutes.
  • Step 3: Check the Bowl – After waiting, look at the water in the toilet bowl. If any of the coloured water from the tank has appeared in the bowl, you have a confirmed leak.

Toilet comparison before and after

Flush washer before and after replacement

🔧 Common Causes of Leaking Toilets


If the test confirms a leak or you can simply hear water constantly running, it’s time to investigate the parts inside the cistern. The two most common culprits are:


  • The Inlet Valve (Fill Valve): Refills the cistern after a flush. If it’s faulty, water will continuously flow into the overflow pipe.
  • The Flush Valve Seal: This rubber washer at the base of the flush valve degrades over time and fails to seal properly, allowing water to seep into the bowl.

For the enthusiastic DIYer, the next step is to take a clear photo of the internal components and search for YouTube tutorials. If you feel confident, you can visit a local hardware store like Bunnings or Mitre 10 to find a matching part.

However, be warned: if you can’t find an exact match, the leak may continue. Many DIY attempts still end with a call to a professional plumber. If you’re not completely confident, calling a professional from the start can save you time, money, and a lot of frustration.


Water leaking from base of toilet pan

🚽 When the Leak Is Outside the Toilet


If you see water pooling on the floor around the base of the toilet, this is a more serious issue. It’s likely caused by a failing seal between the toilet and the sewer pipe.

This situation requires a professional plumber, as the toilet will likely need to be removed and reinstalled. The water leaking onto the floor is contaminated, so it’s important to get it fixed promptly.


Old toilet and new toilet replacement example

♻️ When Should I Replace My Toilet?


We generally recommend replacing your toilet if:


  • It is over 15–20 years old
  • There’s a visible crack in the porcelain (cistern or bowl)
  • You want better water efficiency – Old toilets use 9–12L per flush. Newer models use just 4.5L.

Replacing a toilet isn’t a small decision, and finding one that fits your existing plumbing setup can be tricky. To avoid the hassle, just send us clear front and side photos of your current toilet. We’ll recommend compatible replacement options for you.


🧼 Final Thoughts


A leaking toilet is more than just a nuisance. Whether you take on the challenge yourself or call in an expert, resolving the issue quickly will help you maintain a clean, stable, and water-efficient home.

📞 Call us at 021 837 775

✉️ admin@nexuspgd.com — Email Us

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