We explain how a noisy, water‑wasting toilet in Adelaide can be diagnosed and fixed quickly, and when you should call a licensed plumber. In most homes the cause is one of three parts: the fill valve, the flush valve and chain, or an overflow tube set at the wrong height.
We show simple, safe checks you can do now: set tank water to about an inch below the overflow, inspect the rubber flapper and chain, and test the fill valve for faults. If water rises into the overflow or the flapper is worn, replacement is usually the solution.
We are All Mat Plumbing — qualified, insured and available 24/7 for emergency plumbing across Adelaide. Our fully equipped vehicles carry parts for taps and toilets, burst pipes, hot water systems and backflow testing.
Need help now? Call Marc on 0432 667 785, request a quote today, or email info@allmatplumbing.com.au. Book a plumber in Adelaide for backflow testing or hot water replacement.
Key Takeaways
- Quick checks: set tank level, inspect flapper and chain, test fill valve.
- A faulty fill valve often causes water to enter the overflow tube.
- Clean or replace a worn rubber flapper; short overflow tubes need valve assembly replacement.
- Try safe DIY steps first, but call a licensed plumber for complex or persistent faults.
- All Mat Plumbing offers 24/7 emergency response and services across Adelaide.
Running toilet in Adelaide homes and offices: the problem and the cost
We see this across Adelaide: a steady flow wastes water, damages fittings and raises bills fast.
When water flows into the overflow, the fill valve or its height is often the cause. If water does not reach the overflow, the flapper or flush valve usually leaks. Both scenarios cost money and stress seals and fixings.
Why constant water flow matters for your water bill and fixtures
Even a small leak can add litres each day. That continuous wetting stains the bowl and wears rubber parts. Over time seals fail and leaks spread to floors or ceilings below.
When a running toilet points to bigger plumbing issues
At offices and retail sites, prolonged waste can flag supply pressure faults or corroded fittings upstream. For homes, brittle hoses or aged valves often cause repeat faults.
- Fast action saves on bills and avoids bigger repairs.
- We handle residential and commercial plumbing, 24/7, with fully equipped vehicles.
- Need it fixed now? Request a quote today or Call Marc on 0432 667 785.
| Symptom | Likely cause | Impact |
|---|---|---|
| Water into overflow | High float / faulty fill valve | High water use, vibration wear |
| Water not entering overflow | Worn flapper or faulty flush seal | Continuous leak, staining bowl |
| Intermittent trickle | Weak supply pressure or corroded fittings | Hidden water loss, possible supply repairs |
Before you start: safety, tools, and parts you may need
We begin with safety. Turn off the isolation valve on the inlet line and clear the area around the pan and tank. Protect the floor with towels and place the lid on a soft cloth to avoid chips or cracks.
Turn off the isolation valve and make the area safe
Make sure the valve slot aligns with the pipe to close the water supply. Use a flat-head screwdriver if the slot is stiff. Have a bucket or sponge ready for any residual water.
Tools and materials checklist
For a straightforward DIY fix, gather basic tools and sensible PPE. We recommend gloves and eye protection when working near old fittings or cleaners.
- Channel locks / water pump pliers — for nuts and fittings.
- Screwdriver (flat and Phillips) — for valve slots and brackets.
- Bucket, towels and a sponge — catch spills and protect floors.
- Small container — keep nuts, screws and small parts safe.
- Replacement parts you may need: fill valve, flush valve assembly, flapper, chain, float.
Prefer a licensed plumber? Request a quote today — email info@allmatplumbing.com.au or call 0432 667 785.
| Tool / Part | Purpose | Quick tip |
|---|---|---|
| Channel locks | Grip and turn tank nuts and fittings | Use adjustable jaws for a secure hold |
| Flat-head screwdriver | Align isolation valve slot; adjust brackets | Turn slowly to avoid damaging the valve |
| Bucket & towels | Contain spills and protect flooring | Fold towels under the lid to cushion it |
| Flapper / fill valve | Common parts to replace for leaks | Bring the old part to the store for an exact match |
How a cistern works: water level, fill valve, flush valve, and overflow
We’ll show how the tank stores and moves water so you can spot which part fails.
Float, fill valve, and the set water level below the overflow
Water enters through the fill valve and fills the tank. The float rises with the water and signals the fill valve to shut off.
Set the water about an inch below the overflow. That prevents spillover while keeping enough water for a full flush.
Flapper, chain, and the flush mechanism at the bottom
The flush valve sits at the bottom and holds the flapper. Pressing the lever lifts the chain and frees water into the bowl.
Some designs use a ball float. Others use a float cup. Both stop the fill valve when the set level is reached.
- Storage and release: the cistern stores water in the tank and releases it to clear the bowl.
- Shut-off action: the float rides the water and tells the fill valve when to stop.
- Safety overflow: the overflow prevents flooding but wastes water if the fill valve fails.
- Boosted flow: rim holes or a siphon jet direct extra flow for stronger flushing performance.
Understanding how these parts interact makes diagnosis quicker and avoids guesswork in later steps.
Diagnose the issue fast: where is the water going?
Start by removing the lid and watching the tank refill. This simple step shows whether water rises into the overflow or disappears through the outlet to the bowl. Make the observation before you touch any parts.
If water spills into the overflow tube
If water reaches and spills into the overflow, the float height or the fill valve is likely at fault. Lower the float or replace the fill valve if it fails to shut off. A high water level wastes water and can damage seals.
If water is not entering the overflow tube
When water stays below the overflow, check the flapper at the flush valve outlet. Look for warping, grit or mineral build-up. Clean the sealing surface with warm water and a little vinegar, or fit a new flapper if it’s warped.
Simple checks: chain length, stuck button, or lever linkage
Inspect the chain and lever. A chain that is too tight or too long stops a full seal or prevents a full lift. Check dual‑flush buttons and the lever for binding. Adjust the chain so the flapper closes fully without slack.
- Lift the lid and watch the refill cycle.
- Lower the float or replace the fill valve if water reaches the overflow.
- Clean or replace a warped flapper and set correct chain tension.
- Replace a too‑short overflow by fitting a compatible flush valve assembly.
Need help now? Call our 24/7 emergency line — Marc on 0432 667 785, or request service online at All Mat Plumbing emergency service.
Fix the water level: adjust or replace a faulty fill valve
A correct water height fixes many common tank faults in just a few simple steps. We keep the process safe and simple so you can test the valve and float without fuss.
Set the float height so water sits about an inch below the overflow
Turn off the isolation valve, then flush and sponge any remaining water from the tank.
Adjust the float using the screw or clip on the fill valve in small quarter-turns. Test between adjustments until the water level sits about an inch below the overflow.
Check the float itself for trapped water. A waterlogged float will not shut the valve and must be replaced.
Replace a faulty fill valve and recheck for leaks
If the tank still overfills regardless of float position, replace the fill valve. Turn off the isolation valve, drain the tank, disconnect the supply and undo the locking nut under the tank.
- Remove the old valve and fit the new assembly to the same height.
- Position the refill tube correctly and hand-tighten the locking nut. Reconnect the supply.
- Turn the isolation valve on, let the tank fill and watch for drips at the base and supply connection.
Not confident? We can send a licensed plumber across Adelaide. Call 0432 667 785 or email info@allmatplumbing.com.au.
Stop leaks at the flush: flapper, seal, and chain adjustments
Begin by checking the flapper and chain—these simple parts fix most bowl-side leaks. Turn off the isolation valve and lift the lid. Work safely and place the lid on a towel.
Clean or replace a worn rubber flapper or seal
Inspect the flapper at the bottom of the tank for warping, cracks or grime. Clean the rubber seal and the seat with warm water and a little vinegar to remove mineral build-up.
Flappers usually last three to five years. Replace if warped or brittle for a reliable seal.
Set the chain length so the flapper closes fully
Ensure the chain is long enough for the flapper to sit flat but short enough to lift cleanly when you press the lever or button. Avoid slack that traps under the seal.
Test the flush and watch the bowl for any trickle after the tank refills. Reseat the flapper arms and confirm the lever linkage moves freely.
If the leak continues, the flush valve seat may be worn and need a new assembly. Want us to handle the repair? Request a quote today from All Mat Plumbing.
| Check | Action | Result |
|---|---|---|
| Flapper at bottom | Clean with warm water & vinegar; replace if warped | Stops most water leaks at the seal |
| Chain length | Adjust so flapper closes fully without binding | Prevents continuous trickle into the bowl |
| Lever / button linkage | Reseat arms and test movement | Ensures full lift and clean shut-off |
| Flush valve seat | Inspect if leak persists; replace assembly if worn | Permanent repair for aged parts |
Overflow tube height and compatibility problems
A mismatch in overflow length often causes persistent water loss that simple float tweaks won’t fix. The overflow must sit at the correct level so the tank can fill, stop and protect your bathroom from spills.
When the overflow tube is too short or mis-set
If the tube is cut too short the float can never prevent overflow. That leads to persistent leakage even when the fill valve and float are adjusted.
We note this fault after repairs or when parts are swapped without checking fit. A low tube wastes water and stresses seals.
Replace the flush valve assembly with a compatible part
For a reliable fix we recommend a compatible flush valve replacement. Match the new assembly to your tank so the overflow height and valve seal align.
- Isolate water, drain the tank and disconnect the supply.
- Remove tank-to-bowl bolts and lift the tank carefully.
- Undo the flush valve nut, swap the assembly and fit a new gasket.
- Re-seat the tank, align before tightening bolts, reconnect supply and refill.
If removing the tank feels complex, call us for fast on-site replacement across Adelaide.
| Problem | Cause | Fix |
|---|---|---|
| Constant overflow | Overflow tube too short / wrong fit | Replace flush valve assembly; match height |
| Water loss despite correct float | Mismatched valve or gasket | Install compatible valve and new gasket |
| Tank movement / leaks | Incorrect bolt torque or misalignment | Re-seat tank; tighten evenly and test |
When DIY is not enough: call qualified Adelaide plumbers now
Some problems need trained hands — we respond quickly across Adelaide to sort complex faults safely. If simple checks and adjustments don’t stop a persistent leak, internal assemblies or mismatched parts may be the cause.
What we fix:
- Persistent toilet keeps running after DIY checks — we diagnose and replace incompatible flush assemblies.
- Burst pipes, roof and gutter leaks, and blocked drains cleared with hydro jet service.
- Hot water systems (gas, electric, heat pump, solar), water mains, sewer and stormwater repairs.
Fully equipped vehicles and fast 24/7 response
We are qualified and insured. Our fully equipped vehicles carry parts and tools so we complete most repairs on the first visit. That saves you time and reduces repeat call-outs.
Other services: taps and toilets, water filters, gas fitting and leak detection, commercial backflow and TMVs, grease arresters, plus design and construct for commercial works.
| Service | Benefit | Availability |
|---|---|---|
| Emergency repairs | Fast Adelaide response to limit damage | 24/7 |
| On‑site replacements | Fitted parts and tested supply before we leave | Same‑day where possible |
| Commercial compliance | Backflow, TMVs and system design | Scheduled or urgent |
Need help now? Call our 24/7 emergency line: 0432 667 785 or email info@allmatplumbing.com.au. We’ll send a professional plumber with the right parts and the experience to get the job done.
toilet cistern keeps running: Conclusion
Wrap up with a simple path: find where the leak goes, then fix the part at fault.
Start by setting the water level about an inch below the overflow and test the refill cycle. If water still enters the overflow, you may need a new fill valve or a full flush valve replacement. If the leak comes from the outlet to the bowl, replace the flapper and reset the chain and float.
Restore the water supply, let the tank fill, and watch all connections for drips in real time. If problems persist, call a professional plumber for safe repair or replacement work.
We are qualified, insured and available 24/7 with fully equipped vehicles in Adelaide. Call Marc on 0432 667 785, request a quote, or email info@allmatplumbing.com.au.
