A kitchen sink that won’t drain is one of the most frustrating plumbing problems. It stops you from cooking, cleaning, and using your kitchen properly. Here’s what’s likely causing it and what you can do about it.

Why Is Your Kitchen Sink Blocked?

Grease and Fat Buildup

This is the number one cause of blocked kitchen sinks in Melbourne. When grease goes down the drain, it cools and solidifies on pipe walls. Over time, it narrows the pipe until water can barely pass through.

Food Scraps

Even with a sink strainer, small food particles get through. Starchy foods like rice and pasta are particularly bad — they expand in water and create sticky blockages.

Soap Residue

Soap combines with minerals in Melbourne’s water to form a hard residue called soap scum. This coats pipe walls and catches other debris.

Foreign Objects

Bottle caps, utensil pieces, and other small items sometimes fall into the drain and create instant blockages.

Quick Fixes to Try First

1. Boiling Water

The simplest method and often effective for grease buildup:

• Boil a full kettle of water
• Pour it directly down the drain in 2-3 stages
• Wait a few seconds between each pour
• The heat can melt grease and flush it through

Note: Don’t use boiling water if you have PVC pipes — it can soften the joints.

2. Baking Soda and Vinegar

A natural alternative to chemical drain cleaners:

• Pour half a cup of baking soda down the drain
• Follow with half a cup of white vinegar
• Cover the drain and wait 30 minutes
• Flush with hot water

3. Use a Plunger

A cup plunger (not a flange plunger) works well on sinks:

• Fill the sink with a few centimetres of water
• Place the plunger over the drain, ensuring a seal
• Pump vigorously 15-20 times
• Check if the water drains

If you have a double sink, block the other drain while plunging.

4. Clean the P-Trap

The P-trap is the U-shaped pipe under your sink:

• Place a bucket underneath to catch water
• Unscrew the P-trap connections by hand or with pliers
• Empty the contents into the bucket
• Clean out any debris and grime
• Reattach firmly and test

What NOT to Do

• Don’t use chemical drain cleaners regularly - They can corrode pipes and are harmful to the environment
• Don’t use a wire coat hanger - You could scratch or damage the pipe
• Don’t ignore a slow drain - It will only get worse
• Don’t pour more grease down hoping to flush it - It makes the problem worse

When to Call a Plumber

If your DIY efforts haven’t worked, the blockage is likely deeper in the plumbing system. Call a professional if:

• The blockage keeps coming back
• Multiple drains in your home are slow
• You hear gurgling sounds from the pipes
• There’s a bad smell coming from the drain
• Water is backing up into other fixtures
• You’ve tried the fixes above with no result

How a Plumber Fixes Blocked Kitchen Sinks

Professional plumbers have tools that homeowners don’t:

• Electric drain snake - A motorised cable that breaks through tough blockages
• High-pressure water jetter - Blasts away grease, roots, and debris
• CCTV drain camera - Identifies the exact location and cause of the blockage

These methods are more effective than anything you can buy at the hardware store and won’t damage your pipes.

Preventing Future Blockages

Once your sink is draining freely again, keep it that way:

1. Never pour grease or oil down the drain — collect it in a container and bin it
2. Use a sink strainer — catches food before it enters the pipes
3. Run hot water after washing dishes — helps flush residue
4. Monthly maintenance — pour boiling water down the drain once a week
5. Scrape plates into the bin first — before rinsing in the sink

Get Your Kitchen Sink Flowing Again

If your kitchen sink is blocked and DIY fixes aren’t working, Hankook Plumbing can help. We clear blocked drains across Melbourne’s eastern suburbs with professional equipment and experienced plumbers.

Call 0407 756 172 for fast, affordable drain clearing service.