Brown water from the tap is an unsettling sight, especially when all you wanted was a glass of water or a quick shower. Before you panic, there’s one simple check that tells you a lot. The discolouration usually comes from one of three places: the water network in your street, your hot water system, or the pipes in your home. A cold tap test helps you work out which one, and who to call.

Brown water from your tap: the short answer

Water utilities across Australia commonly explain brown water as sediment, such as iron and manganese, that has been stirred up in the pipes. Here’s the quick version:

Brown at every cold tap, including the one closest to the meter: likely the water network. Run the cold tap gently, and contact Sydney Water if it doesn’t clear.
Brown hot water only: likely your hot water system.
Brown at one tap only: likely that tap or the pipe feeding it.

The quick tap test

Work through these steps in order:

Run the cold tap closest to your water meter, usually the front garden tap. Run it gently, not at full blast.
Watch the colour. Does it clear after running, or stay brown?
Check a cold tap inside. Is that brown too?
Now check the hot water, but only once the cold water is running clear.
Try the one tap you first noticed if it hasn’t been covered yet.

What the results usually mean:

Brown at the front tap and inside: points to the network or the supply coming into your property.
Cold is clear, hot is brown: points to your hot water system.
Everything is clear except one tap: points to that tap or its pipework.

Several NSW water utilities recommend running the tap closest to the meter first, as it helps show whether the discolouration is coming from the main or from inside the property.

It’s the network side

Water utilities explain that sediment such as iron and manganese can settle in water mains, and be stirred up when the flow suddenly changes. That can happen after mains repairs, maintenance or other work in the area.

If you think it’s the network:

Run the front cold tap gently and see if it clears.
Avoid using hot water until the cold water runs clear, so sediment isn’t drawn into your hot water system.
Hold off on laundry, as discoloured water can stain clothes.
Contact Sydney Water on 13 20 90 if the water doesn’t clear, or if you’re not sure what’s happening.

It’s only the hot water

If your cold water runs clear but the hot water is brown, the problem is likely inside your hot water system. Water utilities note that discolouration can come from internal plumbing, including hot water systems.

One thing to check first: mixer taps can draw from the hot water supply even when they’re set to cold. Test a separate cold-only tap if you can.

If the hot water stays brown, it’s worth having a licensed plumber inspect the system. They can check its condition and tell you whether it needs a service, a repair or, in some cases, a replacement. Our hot water repairs team can help. If you end up replacing it, our guide to the heat pump hot water rebate in NSW is worth a read first.

It’s one tap only

If only one tap runs brown, the cause is likely close to that tap.

Check the aerator, the small mesh at the end of the spout. Unscrew it, rinse out any sediment and refit it.
If it’s still brown, the issue may be in the tap itself or the section of pipe that feeds it.

A licensed plumber can find the source and repair or replace the affected tap or pipe.

Older homes and galvanised pipes

Water utilities note that discoloured water can also come from the age and condition of a home’s internal plumbing, particularly corrosion in galvanised iron pipes and fittings.

If you live in an older home, in Blacktown, Penrith, Parramatta or anywhere else, signs worth noting include:

brown water that keeps coming back at the same taps
water that’s often discoloured when a tap hasn’t been used for a while

If your pipes are corroding, a plumber can inspect them and talk through your options. That might mean repairing a section or, if the pipes are in poor condition throughout, replacing them (known as repiping). For help with older homes in the area, talk to our plumber in Blacktown.

This is about your water supply pipes. Drains are a separate system. For drain problems, see our guide to why blocked drains are so common in Blacktown.

Is it safe while it clears?

Under the Australian Drinking Water Guidelines, discoloured water is generally treated as an appearance issue rather than a health one, as several NSW water utilities explain.

Even so, to be safe:

Don’t drink water that looks, smells or tastes unusual. Wait until it runs clear.
Avoid washing clothes until it clears, as it can stain.
If you’re unsure, or it doesn’t clear, contact Sydney Water on 13 20 90.

FAQs

Is brown water from the tap safe to drink?
Discoloured water is generally treated as an appearance issue under the Australian Drinking Water Guidelines. Even so, don’t drink water that looks, smells or tastes unusual. Wait for it to clear, or contact Sydney Water if you’re unsure.

How do I fix brown water coming from a tap?
Run the cold tap closest to your meter gently to see if it clears. If only the hot water is brown, have your hot water system checked. If only one tap is affected, check its aerator, then call a plumber.

What does it mean if my tap water is brown?
It usually means sediment, such as iron or manganese, has been stirred up in the pipes. It can come from the water network, your hot water system or your home’s pipes.

Why is only my hot water brown?
If your cold water is clear, the discolouration is likely coming from inside your hot water system. A licensed plumber can inspect it and recommend a service, repair or replacement.

Should I call a plumber or Sydney Water about brown water?
If the cold water is brown at the front tap and doesn’t clear, contact Sydney Water on 13 20 90. If it’s only your hot water or one tap, call a licensed plumber.

Tips

Run the front cold tap gently, never at full blast, when checking.
Clean your tap aerators after any discoloured water event.
Note the date and time you noticed it, to share with Sydney Water or your plumber.
Photograph the water in a clear glass, to show the colour accurately.

Not sure which side it’s on?

If the test hasn’t given you a clear answer, or the problem keeps coming back, talk to our local plumber in Blacktown. We can work out whether it’s your pipes, your hot water system or one for Sydney Water. Sigma Plumbing is your plumber in Sydney, with a strong focus on Western Sydney.

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