Plumbing

If water leaks directly from the drain area when the sink is in use, the cause is usually a worn gasket, loose fitting, or seal failure rather than pipe rupture. Drain leaks often appear only while water is flowing. In most cases, the issue is mechanical and limited to the drain assembly.

The Most Common Reasons

1. Loose Locknut

The drain fitting beneath the sink may loosen.

2. Worn Gasket

Rubber seals compress and deteriorate over time.

3. Improper Installation

Misaligned drain components may leak under load.

4. Cracked Drain Body

Metal or plastic drains can corrode or crack.

Is This Serious?

Minor if:

• Leak only appears while draining
• Drips are small

More serious if:

• Water spreads under flooring
• Leak continues even when not in use

What You Can Do

• Inspect drain assembly
• Tighten connections
• Replace gasket if needed

For related issues:

→ Sink & Drain Problems Explained
→ Why Is My Sink Leaking Underneath?
→ Plumbing Problems Explained

If water is leaking under your sink, the cause is usually a loose pipe connection, worn washer, or cracked fitting rather than a burst pipe. Most under-sink leaks occur at joints or seals. In many cases, the problem is confined to the cabinet area rather than the wider plumbing system.

The Most Common Reasons

1. Loose Drain Fittings

Connections may loosen over time.

2. Worn Washer or Seal

Rubber washers degrade and allow drips.

3. Cracked Trap or Pipe

Plastic pipes can develop hairline cracks.

4. Supply Line Leak

Flexible supply hoses may leak at fittings.

If taps also drip:

→ Tap Problems Explained

Is This Serious?

Minor if:

• Leak is slow
• Only one joint is wet

More serious if:

• Cabinet wood swells
• Leak continues when taps are off

What You Can Do

• Dry area and identify source
• Tighten fittings carefully
• Monitor after use

For related issues:

→ Sink & Drain Problems Explained
→ Plumbing Problems Explained

If your sink makes noise while draining, the cause is usually trapped air, partial blockage, or venting imbalance rather than a faulty tap. Drain noises often occur when airflow cannot equalise properly. In most cases, the issue is related to the drain system rather than the water supply.

The Most Common Reasons

1. Partial Blockage

Restricted flow causes air to escape in bursts.

→ Why Is My Sink Gurgling?

2. Vent Pipe Issue

Blocked roof vents can force air through the drain.

If toilets also make noise:

→ Why Is My Toilet Gurgling?

3. Shared Drain Line Discharge

Large water discharge from washing machines can affect nearby sinks.

Is This Serious?

Minor if:

• Noise is occasional
• Only one fixture is affected

More serious if:

• Multiple fixtures make noise
• Water backs up

What You Can Do

• Check for slow drainage
• Monitor other fixtures
• Avoid simultaneous heavy water use

For related issues:

→ Sink & Drain Problems Explained
→ Plumbing Problems Explained

If your sink drains slowly, the cause is usually a partial blockage in the trap or drain line from grease, soap, or debris rather than a broken pipe. Slow drainage typically develops gradually as buildup restricts water flow. In most cases, the issue is local to that sink rather than the main plumbing system.

The Most Common Reasons This Happens

1. Blocked U-Bend (Trap)

The curved pipe beneath the sink collects debris over time.

If water does not drain at all:

→ Why Is My Sink Not Draining?

2. Grease or Food Buildup

Kitchen sinks commonly clog from grease solidifying inside pipes.

3. Hair and Soap Residue

Bathroom sinks often accumulate hair and soap.

If your shower also drains slowly:

→ Why Is My Shower Not Draining?

4. Partial Main Line Restriction

If multiple fixtures are slow, the blockage may be deeper.

→ Plumbing Problems Explained

Is This Serious?

Minor if:

• Only one sink is affected
• Drainage improves with plunging

More serious if:

• Multiple drains are slow
• Water backs up elsewhere

What You Can Do

• Clean the trap
• Use a drain snake
• Flush with hot water
• Monitor other fixtures

For related issues:

→ Sink & Drain Problems Explained
→ Why Is My Sink Not Draining?

If your sink smells unpleasant even after cleaning, the cause is usually buildup inside the trap, blocked venting, or stagnant water rather than a broken pipe.

Most sink odours come from trapped debris or sewer gases escaping.

The Most Common Reasons This Happens

1. Dirty U-Bend (Trap)

The curved pipe beneath the sink holds water to block sewer gases.

If debris collects inside, it can rot and produce odours.

This is one of the most common causes.

If your sink also drains slowly, see:

→ Why Is My Sink Not Draining?

2. Food or Grease Buildup

In kitchen sinks, grease and food particles can coat the inside of pipes and begin to smell over time.

3. Dry Trap (Unused Sink)

If a sink hasn’t been used for a long time, the water inside the trap can evaporate.

Without this water seal, sewer gases can rise.

4. Blocked Vent Pipe

If the plumbing vent is blocked, sewer gases may escape through the sink.

If you also hear bubbling or gurgling, see:

→ Why Is My Sink Gurgling?

If toilets are affected too:

→ Why Is My Toilet Gurgling?

5. Deeper Drain Line Issue

If odours are strong and persistent, the issue may be further down the drain line.

See:

→ Plumbing Problems Explained

Is This Serious?

It may be minor if:

• The smell improves after cleaning
• Only one sink is affected
• The trap hasn’t been cleaned recently

It may require attention if:

• Multiple drains smell
• You notice bubbling
• Water backs up

Persistent sewer smells should not be ignored.

What You Can Do

If your sink smells, you can:

• Clean the trap
• Flush with hot water
• Run water in unused sinks
• Monitor other drains

If the smell persists or spreads, inspection may be required.

For related issues, see:

→ Sink & Drain Problems Explained
→ Why Is My Sink Not Draining?
→ Why Is My Sink Gurgling?
→ Why Is My Toilet Gurgling?

→ Plumbing Problems Explained

If water rises back up through your sink drain, the cause is usually a blockage further down the drain line rather than a problem with the sink itself.

Backflow typically indicates restricted drainage or pressure imbalance in the plumbing system.

The Most Common Reasons This Happens

1. Blocked Main Drain Line

If the main drain line is partially blocked, water has nowhere to go and may return through the lowest opening — often the sink.

If multiple fixtures are slow or backing up, see:

→ Plumbing Problems Explained

If your toilet also bubbles, see:

→ Why Is My Toilet Bubbling?

2. Shared Waste Pipe Issue

In some homes, kitchen sinks, washing machines, and dishwashers share a drain line.

When one appliance drains quickly, water may push back into the sink.

If drainage is slow too, see:

→ Why Is My Sink Not Draining?

3. Ventilation Problem

If air cannot enter the drain system properly, water may struggle to flow downward and instead reverse direction briefly.

If you hear gurgling sounds, see:

→ Why Is My Sink Gurgling?

4. Severe Local Blockage

A complete clog close to the sink can also cause water to rise immediately after draining.

Is This Serious?

It may be minor if:

• It happens once
• Only one sink is affected
• The water clears quickly

It may require urgent attention if:

• Multiple fixtures back up
• Sewage appears
• Water rises significantly

Backflow can indicate deeper drain restriction.

What You Can Do

If water is coming back up your sink, you can:

• Stop running water temporarily
• Check other fixtures for slow drainage
• Avoid using appliances connected to the same drain
• Monitor for repeated backup

If multiple fixtures are affected, inspection of the main drain line may be required.

For related issues, see:

→ Sink & Drain Problems Explained
→ Why Is My Sink Not Draining?
→ Why Is My Sink Gurgling?
→ Why Is My Toilet Bubbling?
→ Plumbing Problems Explained

If your sink makes bubbling or gurgling sounds while draining, the cause is usually a partial blockage or venting issue rather than a problem with the tap itself.

Gurgling is normally caused by trapped air in the plumbing system.

The Most Common Reasons This Happens

1. Partial Drain Blockage

When a drain line is partially clogged, water struggles to pass through.

Air gets trapped and released in bursts, creating a gurgling sound.

If your sink drains slowly as well, see:

→ Why Is My Sink Not Draining?

2. Blocked Plumbing Vent

Plumbing systems use roof vents to allow air into pipes.

If a vent becomes blocked, pressure cannot equalise properly.

Air may escape through the sink drain instead.

If your toilet also gurgles, see:

→ Why Is My Toilet Gurgling?

Broader issue:

→ Plumbing Problems Explained

3. Main Drain Line Restriction

If multiple fixtures gurgle or drain slowly, the blockage may be further down the main drain line.

If water backs up elsewhere, see:

→ Why Is Water Coming Back Up My Sink?

4. Sudden Large Water Discharge

If a washing machine or bath drains quickly, it can momentarily affect nearby sinks.

If this happens regularly, it may indicate pressure imbalance.

Is This Serious?

It may be minor if:

• Gurgling happens occasionally
• Only one sink is affected
• Drainage is otherwise normal

It may require attention if:

• Multiple fixtures gurgle
• Water backs up
• Strong odours appear

What You Can Do

If your sink is gurgling, you can:

• Check for slow drainage
• Use a plunger
• Monitor other fixtures
• Listen for repeating sounds

If gurgling affects toilets or showers too, inspection may be required.

For related issues, see:

→ Sink & Drain Problems Explained
→ Why Is My Sink Not Draining?
→ Why Is My Toilet Gurgling?
→ Why Is My Toilet Bubbling?

→ Plumbing Problems Explained