My water has bubbles in it, or looks milky

You fill a glass and the water looks cloudy or milky white, then clears after a minute. Or the tap splutters and spits air. In most cases it's just tiny air bubbles, which are harmless. But sometimes bubbles and cloudy water point to something in the plumbing worth checking. Here's how to tell the difference.

The glass test

Fill a clear glass and leave it on the bench.

Why air gets into the water

• Work on the water main: after Sydney Water repairs or your own water being turned off, air is trapped in the pipes. Run the taps for a few minutes and it clears.
• Cold water under pressure: cold water holds more dissolved air, which comes out as bubbles when the pressure drops at the tap. It's more noticeable in winter.
• High water pressure: very high pressure forces more air into solution. See pressure limiting valves.
• Hot water only: if only the hot water is milky or spits air, the hot water system may be getting air in or overheating. Get it checked.
• Air in a rainwater system: a pump drawing air from a low tank, or a leak on the suction side, can give spluttering taps on tank water.

When to call a plumber

• The water doesn't clear in the glass test.
• Only the hot water is milky, or the hot taps spit and bang.
• Taps keep spluttering long after any water outage.
• The water is discoloured as well. See brown water.

We'll check the pressure, the hot water system and the pipework to find the cause, with a fixed price before any work starts.

In southern Eastern Suburbs homes

High mains pressure in parts of Matraville, Botany and Pagewood, and homes with rainwater systems in Eastgardens and Little Bay, are where we most often see bubbly or spluttering water. In most cases it's air and nothing to worry about, but a quick check gives peace of mind.

Related help: water pressure guide, pressure limiting valves, brown water, water filters and rainwater pumps. Local pages: Matraville, Botany, Pagewood and Eastgardens.