The sink empties slowly after dinner. Then one night the water just sits there with the scraps floating around on top.
Here’s what’s usually happened. Fats and oils go down the drain warm and liquid, then cool a few feet along the pipe and set against the wall like candle wax. Every wash adds another thin layer. Food scraps and coffee grounds stick to it, and the pipe narrows a bit more each week until a sink full of dishwater is more than it can take.
- Water sits in the bowl The drain is restricted and can’t move water away.
- Gurgling after draining Air being pushed back through the water.
- A bad smell near the plug Grease, food and waste sitting inside the pipe.
- It backs up after the dishwasher That’s the biggest volume the drain gets.
- Nearby drains slow too The problem is further along the shared line.
A sink that’s slowing down is on a timetable. It doesn’t stop draining overnight, which means there’s plenty of warning before the blockage is complete. This is one of our regular call-outs across Hurstville, particularly in kitchens where the pipework was never upgraded during a renovation.
Quick answer:
A blocked sink usually means grease, food scraps, soap residue, hair or a restriction further down the pipe is stopping water leaving the sink properly. The minor version only affects one sink and still drains slowly. It gets more serious with bad smells, gurgling, water backing up, or nearby fixtures reacting at the same time, because that points to the shared drain line rather than the sink. Call a plumber when the sink won’t drain at all, the blockage keeps returning, or more than one drain is affected.
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Sink blocked? Let’s clear it properly
Water Workx Plumbing is fully licensed and insured, with clean and tidy Workx from enquiry through to job completion.
What causes blocked sinks?
A sink blocks when waste starts catching inside the pipe instead of washing straight through. The cause matters, because a kitchen sink full of grease needs a different approach to a bathroom basin full of hair and soap buildup. Both narrow the pipe the same way, but they don’t clear the same way.
- Fats, oils and grease Cool inside the pipe and turn sticky, catching everything after them.
- Food waste and coffee grounds Small particles settle in the bend and pack together.
- Hair and soap residue Bathroom basins narrow as hair catches toothpaste, soap and product buildup.
- Pipe scale or old joints Older pipework roughens inside, so waste clings instead of passing.
- Tree roots deeper in the line Roots enter older joints and catch waste passing through.
Sydney Water advises that fats, oils and grease contribute to wastewater blockages, and that hair does not dissolve in water. If the same sink keeps blocking after the top is cleared, the real restriction is sitting deeper than the plug or trap.
How we clear a blocked sink
We check whether the blockage is local to the sink or part of a larger drainage problem. The method follows what’s actually in the pipe, the access point and whether this has happened before.
Dealing with a blocked sink Kingsgrove requires expertise to identify the correct method for clearing the issue.
| Method | Best for |
|---|---|
| High-Pressure Water Jet | Grease, sludge, roots |
| Electric eel | Firm local blockages |
| Flex Shaft | Scale and buildup |
| CCTV camera | Repeat blockages |
A one-off blockage clears once the trap or nearby waste line is dealt with properly. A sink that keeps blocking needs diagnosis, because clearing the closest point without finding the cause leaves grease, roots or pipe damage sitting further along the line.
When to stop and make the call
Clearing scraps from the strainer or draining a visible bit of water from the plug area is reasonable. Pouring harsh chemicals into a sink already full of water, or forcing wire into the pipe, is where it gets harder and less safe.
Safe to try yourself
- Remove visible scraps and debris from the drain opening
- Bin fats and oils instead of rinsing them away
- Use a strainer over the plughole
- Check whether nearby fixtures are slow
- Stop using the sink once it stops draining
Stop and make the call
- The sink won’t drain at all
- The same sink keeps blocking
- Water backs up in another fixture
- A smell keeps returning after cleaning
- Water appears under the cupboard
One thing to skip: Caustic drain cleaners sit behind a blockage and create a hazard for whoever opens the pipe. They also do nothing for tree roots, pipe damage or heavy grease further down the line. If water is backing up or spreading into cabinetry, stop using the sink and get it checked properly.
The bottom line
A slow sink is minor if it clears, stays clear and only affects one fixture. It becomes serious when the same sink blocks again, smells return, gurgling starts, or water backs up somewhere else. Left too long, it turns from a sink problem into a cabinet, floor or cleanup problem.
Dealing with a blocked sink quickly saves you from more extensive repairs further down the line, and a proper diagnosis beats another quick clean-out. Once the line is checked, you’ll know whether the cause is grease, food waste, hair, roots, pipe damage or something deeper.
Sink still not draining? Let’s sort it out
Water Workx Plumbing looks after homes across Hurstville and the surrounding suburbs. We’ll clear the drain, explain what caused the blockage and give you a fixed price before any work starts. Call Peter and the team.
Blocked Sink FAQs
Why does my kitchen sink keep blocking?
Fats and oils go down warm, then cool and set inside the pipe. Food scraps stick to that layer, and the pipe narrows until a sink full of water is too much for it.
Why does my bathroom basin drain slowly?
Hair catches in the bend under the basin, and soap and toothpaste stick to it. The two together form a soft plug that water struggles to get past.
Can I pour boiling water down a blocked sink?
Hot water can help shift a very early grease buildup, but boiling water risks damaging plastic pipework and seals, and it won’t touch a solid blockage.
How much does blocked sink clearing cost?
It depends on where the blockage sits and what’s causing it. Buildup near the trap is a straightforward clear, while grease or roots further along take longer.
When should I call a plumber for a blocked sink?
When the sink won’t drain at all, when it keeps blocking after being cleared, or when more than one drain in the house is running slow.
Water Workx Plumbing is fully licensed and insured, with clean and tidy workmanship, upfront pricing and a lifetime labour guarantee.
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