A leaking flexi hose under the sink is a common household problem, and it can go from a small drip to a decent amount of water damage very quickly. The good news is that if the hose is simply loose or the washer has failed, it may be a straightforward fix. The key is to act early, turn the water off, and know when the job needs a licensed plumber.
What Is a Flexi Hose and Why Does It Leak?
A flexi hose is the braided, flexible hose used to connect taps and fixtures to the water supply under a sink or basin. You’ll usually find them under kitchen, bathroom, or laundry sinks. In Australian homes, they are common because they make installation easier and allow a bit of movement in tight spaces.
Leaks usually happen for one of a few reasons: the connection has loosened over time, the rubber washer inside the fitting has worn out, the hose braid or inner liner has split, or the hose is old and corroded. In some cases, the leak is not actually from the hose body itself but from the threaded connection at the tap or water outlet.
What You Should Do First
If you spot water under the sink, turn off the water supply as soon as possible. Most sinks have individual isolation valves on the wall or inside the cabinet. Turn them clockwise until they stop. If there are no local isolating valves, you may need to turn off the main water supply for the property.
Then dry the area and check where the water is coming from. Put a dry paper towel around the hose, nut, and tap connection to help pinpoint the leak. If water is spraying, the hose is bulging, or the braid is damaged, stop using the fitting and replace it or call a plumber.
Also, avoid leaving a leaking hose unattended. Water can damage cabinets, flooring, and nearby electrical outlets. If water has reached power points or appliances, switch off power at the board if it is safe to do so and call a licensed professional.
Can You Fix It Yourself?
Some minor flexi hose leaks can be sorted by a capable DIYer, but plumbing work in Australia is regulated. If the repair involves altering pipework, replacing fixed plumbing fittings beyond a simple like-for-like hose swap, or anything you are unsure about, use a licensed plumber. State and territory licensing bodies and Fair Trading agencies apply different rules, and the National Construction Code also sets standards for plumbing installations.
If the hose is a basic screw-in type and you are only replacing it with the same style and size, many homeowners are comfortable doing that. However, if the hose is behind a wall, part of a dishwasher connection, connected to a mixer tap with hard-to-access fittings, or showing signs of broader plumbing issues, it is best left to a professional.
Tools and Materials You May Need
- Bucket or towel
- Adjustable spanner
- Replacement flexi hose with matching thread and length
- New rubber washers, if required
- Plumber’s tape only if the fitting type calls for it
- Flashlight
How to Replace a Leaking Flexi Hose
Before buying a replacement, take the old hose with you to Bunnings or Mitre 10 so you can match the thread size, fitting type, and length. A hose that is too short may be under strain, while one that is too long can kink.
To replace it:
- Turn off the water supply and open the tap to release pressure.
- Place a bucket and towel under the fitting.
- Use an adjustable spanner to loosen the hose nuts carefully.
- Remove the old hose and check the washers for damage or flattening.
- Fit the new hose, making sure the connections are straight and not cross-threaded.
- Tighten the nuts firmly, but do not overtighten.
- Turn the water back on slowly and check for leaks.
If the leak continues after replacing the hose and washers, the issue may be with the tap body, valve seat, or the threaded connection itself. That is a good time to call a licensed plumber.
Common Mistakes to Avoid
| Problem | Why It Causes Trouble | Better Approach |
|---|---|---|
| Overtightening the nuts | Can crush washers and damage fittings | Snug, firm tightening only |
| Using the wrong hose length | Creates stress, kinks, or twisting | Match the original length as closely as possible |
| Reusing a damaged washer | Old washers often won’t seal properly | Replace washers when changing the hose |
| Ignoring corrosion or bulging | Signals the hose is near failure | Replace the hose immediately |
When to Call a Licensed Plumber
Call a licensed plumber if the hose is burst, the leak is coming from a concealed area, the valve will not shut off, or you see repeated leaks after a replacement. You should also get help if there is water damage to cabinetry, mould growth, or any concern about nearby electrical wiring.
In Australia, plumbing work is not something to guess at. A licensed plumber can check compliance, replace faulty fittings properly, and make sure the installation meets local requirements under the National Construction Code.
Preventing Future Leaks
Once the immediate issue is sorted, a few simple habits can reduce the chance of another leak. Check under sinks every few months for moisture, rust, or bulging hoses. Make sure the hoses are not rubbing on sharp cabinet edges or pinched behind bins or drawers. If a hose is old, cracked, or heavily braided, replace it before it fails.
In homes exposed to hot summers and big temperature swings, rubber parts can age faster. A quick inspection before summer and after any renovation or appliance work is a smart habit.
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