Low water pressure makes everything harder — showers are weak, taps take forever to fill a sink, and appliances don’t work properly. Here are the most common reasons for low water pressure and what you can do about it.

Check These Simple Things First

Is It Just One Tap or the Whole House?

This is the most important question. If only one tap has low pressure, the problem is localised. If it’s the whole house, the cause is likely further upstream.

Has Your Water Authority Notified You?

Check your water authority’s website or app (Yarra Valley Water, South East Water, or City West Water) for planned works or outages in your area. Nearby water main repairs can temporarily reduce pressure.

Are Your Neighbours Affected Too?

If your neighbours also have low pressure, the issue is likely with the mains supply, not your plumbing.

Common Causes of Low Water Pressure

1. Partially Closed Valves

The most common — and easiest to fix — cause. Check these valves:

• Water meter valve — Located at your water meter near the street. Make sure it’s fully open
• Main shut-off valve — Usually where the water line enters your house. Ensure it’s fully open
• Isolation valves — Under sinks and behind toilets. Someone may have partially closed one

Even a quarter-turn can significantly reduce pressure.

2. Clogged Aerators or Showerheads

If low pressure affects only specific taps or your shower, mineral buildup in the aerator or showerhead is likely the cause.

Fix: Unscrew the aerator or showerhead and soak it in white vinegar overnight. Scrub with an old toothbrush and reattach.

3. Corroded or Blocked Pipes

In older Melbourne homes with galvanised steel pipes, internal corrosion gradually narrows the pipe diameter. Mineral deposits and rust build up over decades until water can barely pass through.

Fix: This requires professional assessment. Partial or full repiping may be needed.

4. Leaking Pipes

A hidden leak diverts water before it reaches your taps, reducing pressure. Signs of a hidden leak include:

• Unexplained wet spots on walls, ceilings, or floors
• Higher than normal water bills
• Water meter moving when all taps are off

Fix: A plumber can locate the leak using specialist detection equipment.

5. Faulty Pressure Regulator

Some Melbourne homes have a pressure reducing valve (PRV) installed where the water line enters the property. If this valve fails, it can restrict flow too much.

Fix: A plumber can test and replace the PRV if faulty.

6. Peak Demand

Water pressure can drop during high-demand times — early morning and evening when many households are using water simultaneously. If pressure is fine at other times, this is likely the cause.

7. Hot Water System Issues

If only your hot water has low pressure, the problem is likely with your hot water system:

• Blocked inlet filter — Many systems have a filter that can clog
• Failing tempering valve — The mixing valve can restrict flow
• Sediment in the tank — Reduces the effective volume and flow

When to Call a Plumber

Contact a professional if:

• Low pressure affects the whole house
• The problem has gradually worsened over time
• You suspect a hidden leak
• Only hot water pressure is low
• You’ve checked valves and aerators with no improvement
• Your home has old galvanised pipes

What a Plumber Can Do

Professional solutions for low water pressure include:

• Pressure testing — Measuring exact pressure to identify the problem
• Leak detection — Finding hidden leaks that reduce pressure
• Pipe replacement — Upgrading corroded pipes to modern materials
• Pressure pump installation — Boosting pressure where mains supply is insufficient
• PRV adjustment or replacement — Ensuring the regulator is working correctly
• Hot water system servicing — Clearing filters and valves

Hankook Plumbing Can Help

If you’re dealing with low water pressure in Melbourne’s eastern suburbs, we can diagnose the cause and provide the right solution. Call 0407 756 172 for a professional assessment.