Troubleshooting Guides · Diagnose & Fix · Updated 2025
Bathroom Problems —
Diagnose & Fix Fast
Running toilet, clogged drain, mystery leak — every common bathroom problem diagnosed and fixed with step-by-step guides. Written by plumbers, tested in real bathrooms.
9+
Problem Guides
3
Fixture Types
DIY
Friendly Fixes
⚠️
Active leak or flooding? Stop the water first.
Turn off the isolation valve behind the toilet or under the sink — usually a quarter-turn clockwise. Then use our guides below to diagnose and fix.
Toilet Keeps Running ◆
Toilet Won’t Flush ◆
Toilet Leaking ◆
Toilet Smell Problem ◆
Low Water Pressure Shower ◆
Shower Drain Clogged ◆
Shower Leak Problem ◆
Sink Drain Clogged ◆
Sink Leak Problem ◆
Toilet Keeps Running ◆
Toilet Won’t Flush ◆
Toilet Leaking ◆
Low Water Pressure Shower ◆
Shower Drain Clogged ◆
Sink Drain Clogged ◆
Toilet Problem · Fix in 15–30 min
Toilet Keeps Running
A constantly running toilet wastes up to 200 litres per day and adds significantly to your water bill. The most common cause is a worn flapper — a $5 part you can replace yourself.
| Symptom | Most Likely Cause | DIY Fix | Difficulty | Cost |
|---|---|---|---|---|
| Runs continuously after flush | Worn flapper valve not sealing | Replace flapper ($5–$15 part) | Easy | $5–$15 |
| Runs for 30–60 sec after flush | Fill valve slow or faulty | Adjust or replace fill valve | Easy | $15–$40 |
| Intermittent running (ghost flush) | Slow flapper leak dropping water level | Replace flapper, check flush valve seat | Easy | $5–$20 |
| Water running into overflow tube | Float set too high | Adjust float arm/ball down | Easy | $0 |
| Running even with lid off, all parts OK | Corroded flush valve seat | Replace flush valve seat or full cistern kit | Moderate | $30–$80 |
💧Step-by-Step
Toilet · Running
How to Fix a Toilet That Keeps Running: Complete Guide
Flapper, fill valve, float and flush valve — we cover every cause with photos and exact steps.
🔧DIY
Toilet · Flapper
How to Replace a Toilet Flapper in 10 Minutes
The single most common fix for a running toilet. No tools needed, costs under $15.
⚙️DIY
Toilet · Fill Valve
How to Replace a Toilet Fill Valve: Step-by-Step
When adjusting the float doesn’t work — replace the full fill valve assembly in 30 minutes.
Toilet Problem
Toilet Not Flushing Properly
Weak, partial or no flush at all — each symptom points to a different fault. Here’s how to read the symptoms and fix the right thing first time.
Weak
Flush
Weak or Slow Flush — Causes & Fixes
Usually low water level in cistern, partially blocked rim jets, or a slow-opening flush valve. All fixable without a plumber in most cases.
Difficulty: Easy
Time: 15–30 min
Cost: $0–$30
Read Fix Guide →
No
Flush
Toilet Won’t Flush At All — Diagnosis
Button or handle not connected, broken flush valve, no water in cistern, or a blockage. We walk through the diagnosis checklist so you know exactly what to fix.
Difficulty: Easy–Med
Time: 20–45 min
Cost: $0–$60
Read Fix Guide →
Toilet Problem · Urgent
Toilet Leaking — Where Is It Coming From?
The location of the leak tells you exactly what’s wrong. Base, cistern, between tank and bowl — each needs a different fix.
01
Leak from the Base
Water pooling around the bottom of the toilet after flushing. Almost always a failed wax seal (floor-mount) or loose pan connector. Replace the wax ring — a 45-minute job if you’re comfortable disconnecting the toilet.
02
Leak from the Cistern
Water dripping or running down the outside of the cistern. Usually condensation (normal in humid bathrooms), a cracked cistern, or a leaking inlet valve. Dry the outside and observe — if it reappears immediately, the inlet valve needs replacing.
03
Leak Between Tank & Bowl
Water seeping from the connection between the cistern and the pan. The spud washer or tank bolts are the culprit. Tighten the bolts evenly first — if that fails, replace the spud washer ($5 part).
Toilet Problem · Root Cause Fix
Toilet Smell Problem — Stop It Permanently
A smelly bathroom isn’t a hygiene problem — it’s a diagnostic one. The smell tells you exactly where to look. Here’s how to read it.
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Sewer / Sulphur Smell
Dry P-trap — Run water in unused drains and check wax seal.
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Urine / Ammonia Smell
Urine under toilet base or inside pan cavity — clean with enzyme cleaner.
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Musty / Damp Smell
Mould behind toilet or under base. Check for slow leak at wax seal or pan collar.
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Intermittent Smell
Blocked vent stack causing siphoning of P-trap — needs a plumber to diagnose.
Cluster 2 · Shower Problems
Shower Problems — Diagnose & Fix
Low pressure, clogged drain, mystery leak — every common shower problem with step-by-step fixes. Most can be resolved without a plumber.
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Low Pressure
Low Water Pressure in Shower
Blocked shower head, faulty mixer, partially closed isolator or a building pressure problem. Each has a distinct fix — start with the simplest.
Difficulty: Easy–Med
Time: 10–30 min
Diagnose & Fix →
🌀
Clogged Drain
Shower Drain Clogged
Water pooling in the shower base? Almost always hair and soap scum. Clear it in 10 minutes with a drain snake or enzyme cleaner — no chemicals needed.
Difficulty: Easy
Time: 10–20 min
Clear the Drain →
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Leak
Shower Leak Problem
Leaks through the floor, grout or screen — each type requires a different repair. A failed waterproof membrane is the most serious and must be fixed immediately.
Difficulty: Med–High
Time: 1–3 days
Find & Fix the Leak →
Shower Problem · Most Searched
Low Water Pressure in Shower — 6 Causes, 6 Fixes
Start with the shower head — a blocked head is the cause in 60% of cases. Takes 10 minutes and costs nothing.
| Cause | How to Confirm | Fix | DIY? | Cost |
|---|---|---|---|---|
| Blocked shower head | Remove head, test pressure from arm — strong? Head is blocked. | Soak in white vinegar 2–4 hours. Replace if beyond cleaning. | Yes | $0–$80 |
| Partially closed isolator valve | Locate isolator valve on supply pipe — check it’s fully open (inline). | Turn to fully open position. | Yes | $0 |
| Faulty shower mixer / cartridge | Pressure OK from head but low at mixer outlet. | Replace mixer cartridge or full mixer valve. | Moderate | $30–$120 |
| Kinked or corroded supply pipe | Inspect accessible pipe runs. Older homes with galvanised pipe. | Replace section of pipe — plumber recommended. | Plumber | $200–$600 |
| Low building/mains pressure | Test pressure at multiple outlets — all low? Building issue. | Install pump booster or contact water authority. | Plumber | $400–$1,200 |
| Shower head flow restrictor | Unscrew head — look for a plastic disc inside the inlet. | Remove restrictor disc (check local water regs first). | Yes | $0 |
🌀
Fix Guide · Clogged Drain
How to Unclog a Shower Drain: 5 Methods That Actually Work
From the $3 drain hook to enzymatic cleaners to a proper drain snake — ranked from easiest to most effective. Plus how to stop it clogging again.
01
Shower Leak · Grout
Leaking Shower Grout: Repair vs Regrout vs Re-waterproof
02
Shower Leak · Membrane
Failed Shower Waterproofing: Signs, Tests & What It Costs to Fix
03
Shower Drain · Odour
Smelly Shower Drain? How to Clean It & Keep It Fresh
04
Shower Screen · Leak
Shower Screen Leaking at the Bottom: Fix It in 30 Minutes
Cluster 3 · Sink Problems
Sink Problems — Diagnose & Fix
Clogged basin drain or a mystery drip under the vanity — both are straightforward to diagnose and fix yourself.
🌀
Clogged Drain
Sink Drain Clogged — Clear It in 10 Minutes
Basin drains clog with toothpaste, hair and soap. The pop-up waste assembly catches most of it right at the top — clear that first before reaching for chemicals.
Difficulty: Easy
Time: 10–20 min
Cost: $0–$15
Read Fix Guide →
🌊
Leak
Sink Leaking — Find It Fast, Fix It Right
Dripping from the tap body, from the supply lines, or from the drain waste? Each tells a different story. We guide you through a 3-minute visual inspection to find the source.
Difficulty: Easy–Med
Time: 20–60 min
Cost: $0–$50
Read Fix Guide →
Sink Drain · Most Common Fix
Clogged Sink Drain: The 4-Step Fix
01
Remove & Clean the Pop-Up Waste
Lift or unscrew the pop-up plug from the drain. A build-up of hair and soap scum around the pivot rod is the most common cause. Clean it thoroughly — this fixes 70% of slow basin drains.
02
Try the Plunger
Cover the overflow hole with a wet cloth, place a cup plunger over the drain, and plunge 10–15 times with force. This dislodges blockages further down the trap without dismantling anything.
03
Remove & Clear the P-Trap
Place a bucket under the P-trap under the sink. Unscrew the two slip-joint nuts by hand (no tools needed for plastic), remove the trap and clear the blockage. Rinse and refit.
Important
When to Call a Plumber (Don’t DIY These)
Active flooding or burst pipe
Turn off the main water supply immediately, then call a licensed plumber. Do not attempt to repair under live pressure.
Moving plumbing or adding fixtures
Any work that involves relocating pipes, adding new wet areas or changing drainage requires a licensed plumber in most regions.
Leak inside a wall or under the slab
If you can hear water but can’t see it, or notice damp patches on walls/floors, call a plumber with leak detection equipment immediately.
Low pressure affecting the whole property
If every fixture in the home has low pressure, the issue is the mains supply or a main isolator — a plumber or water authority job, not DIY.
Persistent sewer smell throughout the home
A sewer gas smell (hydrogen sulphide) that doesn’t clear after running drains and checking traps could indicate a vent stack issue — needs professional inspection.
Failed shower waterproofing membrane
A shower leaking through the floor into the room below is a structural issue. Rectification requires full tile removal, re-waterproofing and retiling — get a licensed waterproofer.
Common Questions
Bathroom Problems FAQ
How much does it cost to fix a running toilet?
Most running toilets are fixed by replacing the flapper ($5–$15) or fill valve ($15–$40). If you do it yourself, the total cost is under $40. A plumber will typically charge $80–$150 call-out plus parts. The job takes 20–30 minutes.
Why does my toilet smell even when clean?
A clean-looking toilet can still smell due to: urine soaked into the base seal, a dry P-trap in a nearby drain, a failing wax ring leaking sewer gas, or a blocked vent stack. The smell type is the best diagnostic clue — sewage = P-trap or seal, urine/ammonia = base seal or pan cavity.
Is low shower pressure a plumbing problem or a shower head problem?
Start by removing the shower head and turning on the supply. If pressure from the arm is strong, the head is blocked or restricted — clean or replace it. If pressure from the arm is also low, the issue is upstream: an isolator valve, cartridge, or supply line. Only if all fixtures in the home have low pressure does it become a plumbing/mains issue.
How do I know if my shower is leaking through the floor?
Signs include: damp smell in the room below after showering, water stains on the ceiling below the bathroom, mould at grout lines that keeps returning despite cleaning, or tiles that sound hollow when tapped (indicating water under the substrate). Do a flood test — block the drain, fill the shower 50mm deep, mark the water level, and check after 30 minutes. If the level drops, you have a membrane failure.
Can I use drain cleaner (caustic) to unblock a shower drain?
We don’t recommend caustic drain cleaners. They damage PVC pipes and chrome fittings over time, are hazardous to handle, and don’t work on hair blockages (they dissolve soap, not hair). Use a drain snake or enzyme-based cleaner instead — both are safer, cheaper and more effective for bathroom drains.
Why does my sink drain slowly but isn’t fully blocked?
A slow (not fully blocked) sink drain is almost always a partial blockage at the pop-up waste, on the pivot rod, or in the P-trap. Remove the pop-up assembly and clean the hair/soap build-up — this clears 80% of slow basin drains in under 5 minutes. If it’s still slow after that, the blockage is further down and needs a drain snake.
Latest
Recent Troubleshooting Articles
💧
Toilet · Running
Why Your Toilet Runs Every 10 Minutes (Ghost Flush) & How to Fix It
Ghost flushing wastes thousands of litres a year. It’s almost always a slow flapper leak — here’s the 10-minute fix.
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Shower · Drain
How to Stop Your Shower Drain Clogging Every Month
A $3 hair catcher prevents 90% of shower drain blockages. We test five types and rank them by how well they actually work.
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Sink · Leak
That Drip Under Your Vanity: 6 Sources and How to Fix Each One
Supply lines, waste joints, tap body, pop-up seal — we photograph every leak source so you can identify and fix yours in under an hour.