How to Unblock a Drain: 7 Methods That Actually Work

Updated July 2026 · 8 min read · Geelong Emergency Plumbing

A blocked drain never happens at a convenient time. It happens ten minutes before guests arrive, or on the first morning of a long weekend, or — in true drain fashion — both at once. The good news is that a decent share of household blockages can be cleared with things you already own, if you work through the methods in the right order.

This guide covers seven methods to unblock a drain, from gentlest to most serious, including which ones are urban myths, which ones quietly damage your pipes, and the point at which DIY stops being thrifty and starts being expensive. It's written for Australian homes — so yes, we'll talk about what our clay soils and thirsty gum trees do to your pipes too.

First: Work Out What Kind of Blockage You Have

Thirty seconds of diagnosis saves an hour of mess. Ask two questions:

• Is only one fixture blocked? One slow sink or shower usually means a local blockage — hair, soap scum or grease sitting close to the drain opening. Great news: these are the DIY-friendly ones.
• Are multiple fixtures blocked, gurgling or smelly? If the toilet gurgles when the sink drains, or several drains are slow at once, the problem is deeper in your sewer line. No amount of plunging one sink fixes a main-line blockage — check our guide on the signs of a blocked sewer drain before wasting your Saturday.

Method 1: Boiling Water (The Two-Minute Fix)

Best for: kitchen sinks with grease build-up.

Boil the kettle and pour the water down the drain in two or three stages, letting each pour work for several seconds. Hot water re-liquefies fats and soap that have congealed inside the pipe. It's free, it takes two minutes, and it fixes more slow kitchen sinks than any product at the supermarket.

One warning: if you have older PVC pipes, use very hot tap water rather than a rolling boil — sustained boiling water can soften PVC joints. And never pour boiling water into a porcelain toilet bowl; the thermal shock can crack it, which converts a $0 fix into a $400 one.

Method 2: The Humble Plunger (Used Properly)

Best for: blocked toilets, sinks and showers with a solid obstruction.

Most people plunge wrong — short, violent jabs that splash more than they shift. The technique that works: cover the drain completely, ensure there's enough water to submerge the plunger cup, push down slowly to expel air, then pull up sharply. The upstroke does the work, yanking the blockage back toward you rather than ramming it deeper. Repeat 10–15 times before judging results.

Two plunger tips the internet forgets: block the overflow hole in a sink with a wet cloth first (otherwise you're just pumping air), and use a flange plunger — the one with the extra rubber sleeve — for toilets.

Method 3: Baking Soda and Vinegar (Yes, It Works — Within Limits)

Best for: light grease, soap scum and smelly drains.

Pour one cup of baking soda into the drain, follow with one cup of white vinegar, and plug the drain while the fizzing does its thing for 20–30 minutes. Flush with hot water. The reaction physically agitates light build-up loose and neutralises odours while it's at it.

Let's be honest about its limits, though: baking soda and vinegar will not dissolve a wad of wet wipes, a hairball with structural integrity, or a tree root. It's maintenance and mild-blockage territory — think of it as a gym session for your drain, not surgery.

Method 4: The Wire Hook (For Hair, the Bathroom Menace)

Best for: bathroom sinks and shower drains.

Straighten a wire coat hanger, bend a small hook into one end, remove the drain cover, and go fishing. What you pull out of a shower drain will haunt you — hair binds with soap scum into a substance science hasn't fully classified — but this method clears most shower blockages completely, for free, in ten minutes. Wear gloves. Trust us on the gloves.

Method 5: A Drain Snake (The Step Up)

Best for: blockages deeper than arm's reach but before the main line.

A hand-cranked drain snake (also called a plumber's auger) costs $15–$40 at any hardware store and reaches one to three metres into the pipe. Feed it in until you feel resistance, crank the handle so the coiled tip screws into the blockage, then either pull the mess back out or break it up. Work gently around bends — forcing a snake through a P-trap can scratch or pierce older pipes.

If a domestic snake hits something solid that won't budge, stop. That's often a root mass or a collapsed section, and pushing harder only wedges the snake into the problem. (Plumbers keep a special shelf of stories about retrieving stuck drain snakes.)

Method 6: A Wet/Dry Vacuum (The Underrated One)

Best for: solid objects near the drain opening — jewellery, toys, the toothpaste cap.

Set the vac to liquids, create the tightest seal you can over the drain (a rubber plunger head with a hole cut for the hose works well), and let suction pull the blockage up instead of pushing it deeper. This is the method that saves engagement rings.

Method 7: Chemical Drain Cleaners (Read This Before You Pour)

Best for: honestly? Rarely your first choice.

Caustic soda and supermarket drain gels do dissolve hair and grease, but they come with fine print nobody reads: they generate heat that can warp PVC and crack older pipes, they're dangerous if they splash back (and a blocked drain full of caustic solution is now a hazard for whoever works on it next — including you), and they do nothing at all against wipes, roots or collapsed pipes. If you use one, use it exactly per the label, never mix products, and never follow a failed chemical attempt with a plunger — pressurised caustic splash-back is an emergency-room classic.

What Not to Do (The Hall of Shame)

• Don't use a pressure washer down the drain. Domestic pressure washers aren't hydro jetters; without the right nozzles they blow apart pipe joints.
• Don't mix chemicals. Bleach plus other cleaners can produce genuinely dangerous gases.
• Don't ignore a recurring blockage. A drain that blocks every couple of months isn't unlucky — it has an underlying fault, usually tree roots or a damaged pipe, and it will keep charging you rent in plunger time until it's properly fixed.

When to Put the Plunger Down and Call a Professional

DIY has a natural finish line. Cross any of these and it's time to call:

• More than one fixture is blocked or gurgling (main sewer line territory)
• Sewage is backing up into the shower, toilet or overflow gully outside
• The same drain keeps re-blocking despite your best work
• You can smell sewer gas indoors
• Thirty minutes of honest effort has moved nothing

At that point the fix involves CCTV drain cameras, high-pressure jetting or root cutting — equipment that finds and fixes the actual cause instead of treating the symptom for the fourth time this year.

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Related guides: What causes blocked drains? · How to clear a blocked outside drain · Blocked drain clearing in Geelong