The Most Common Toilet Problems (and How to Fix Them)
Toilets are one of the most used fixtures in every home — so when something goes wrong, you notice it fast. Two of the most common questions Melbourne homeowners search are:
“Why is my toilet leaking?”
“Why is my toilet constantly running?”
Below is a simple, practical breakdown of the most common causes and what you can do about them — without the American terminology you see online.
Why Is My Toilet Leaking?
A leaking toilet doesn’t always mean water on the floor. Leaks can happen inside the cistern, into the bowl, or around the base.
1. Leak from the cistern into the bowl]
The most common cause is a worn or damaged outlet valve seal (the rubber seal that lifts when you flush and drops back down to stop the water flow).
Signs:
- Toilet bowl water ripples even when no one has flushed
- Cistern refills randomly
- You hear water trickling
2. Leak around the base of the toilet
This is usually caused by a failing pan collar (wax/rubber seal), loose fixing bolts, or a cracked toilet base.
Signs:
Water pooling around the toilet
Smelly water
Stains on tiles or vinyl
3. Leak from the water supply line / fittings
Flexible hoses and inlet valves can wear out over time.
Signs:
- Water dripping down the side of the cistern
- Dampness behind the toilet
- Water damage on flooring
4. Cracked cistern or bowl
Older toilet suites or hairline cracks can cause slow, hard-to-spot leaks.
Why Is My Toilet Constantly Running?
A running toilet wastes hundreds of litres of water a day — and it’s usually caused by something inside the cistern.
1. Worn or damaged outlet valve seal
If the outlet valve isn’t sealing properly, water slowly escapes into the bowl, causing the cistern to constantly top itself up.
Common reasons:
- Rubber outlet seal has hardened
- Mineral buildup
- Seal is not sitting flush
- Outlet valve mechanism is worn
2. Faulty inlet valve (fill valve)
If the inlet valve doesn’t shut off properly, the cistern will continue to fill.
Signs:
Water running continuously
Water flowing into the overflow pipe
Cistern never reaches the right level
3. Float not set correctly
If the float is set too high, the cistern will overfill and send water straight into the overflow pipe.
4. Debris or buildup inside cistern components
Melbourne’s water is treated but still carries fine sediment — over time this can stop seals and valves from working properly.
What You Can Try at Home
1. The food colouring test
Add a few drops of food dye into the cistern and wait 10–15 minutes.
If the colour appears in the bowl → your outlet valve is leaking.
2. Open the cistern lid and check:
- Is the water level too high?
- Is water flowing into the overflow pipe?
- Is the outlet valve seal cracked, twisted, or worn?
- Is the inlet valve shutting off?
When to call a plumber
- Water leaking around the toilet base
- Constant running even after basic checks
- Cracked cistern or bowl
- Outlet valve or inlet valve replacements
- Old toilets with ongoing problems
These issues can escalate quickly — especially leaks at the base, which can soak subfloors or damage tiles.
Toilet Problems in Melbourne Homes
Homes in Melbourne’s eastern suburbs often have older toilet suites, high water pressure, or ageing inlet valves — all of which contribute to leaks and running toilets.
Regular maintenance and quick repairs prevent:
- High water bills
- Damage to flooring and walls
- Mould, smells, and staining
- Unexpected breakdowns (always seems to happen at night!)
Need a hand? We fix leaking and running toilets every day.
Whether your toilet is leaking, constantly running, weak when flushing, or just getting old — we can repair or replace it quickly.