Replacing a flexi hose under your bathroom vanity might look like a simple job, but in New Zealand it's classified as restricted plumbing work under the Plumbers, Gasfitters, and Drainlayers Act 2006. That means, in most cases, you'll need a licensed tradesperson to do it legally. Read on to understand exactly where the line is drawn, why flexi hoses matter so much, and what your options are.
Why Flexi Hoses Are a Big Deal
Flexi hoses — those short, braided stainless-steel hoses connecting your tap or mixer to the water supply — are one of the most common causes of serious water damage in NZ homes. They can fail suddenly and without warning, releasing a full mains-pressure flow of water into your vanity cabinet and beyond. A failed flexi hose can dump hundreds of litres of water in a matter of hours, causing significant damage to floors, walls, and cabinetry. Replacing an ageing or damaged hose promptly is genuinely important.
What Counts as Restricted Plumbing Work in NZ?
Under NZ law, any work that connects to or disconnects from the pressurised water supply system is restricted plumbing work. This includes:
- Removing and replacing a flexi hose connected to the water supply
- Replacing tap valves or mixer taps
- Any work on pipes behind the wall
Restricted work must be carried out by — or directly supervised by — a licensed plumber registered with the Plumbers Gasfitters & Drainlayers Board (PGDB). Doing this work yourself, or hiring an unlicensed person, is illegal and could void your home insurance.
What Can a Homeowner Do?
There are a few things you can legally do yourself:
- Turn off the water supply at the isolating valve (the small tap on the flexi hose itself, or at the toby/main stopcock outside)
- Mop up water and manage immediate leak damage
- Inspect hoses for signs of wear, corrosion, or bulging
- Purchase replacement parts ready for your plumber
You cannot legally remove the old hose and install the new one yourself, because that involves disconnecting and reconnecting to the pressurised supply.
How to Spot a Flexi Hose That Needs Replacing
Get into the habit of checking under your vanity every year or so. Look for:
- Rust or corrosion on the braided outer sleeve
- Bulging or ballooning of the hose body
- Kinks or sharp bends in the hose
- Drips or moisture around the fittings
- Age — most manufacturers recommend replacing flexi hoses every 5–10 years, though always check the specific product's guidance
If you spot any of these warning signs, turn off the isolating valve and call a licensed plumber promptly.
What the Job Involves (So You Know What to Expect)
When a licensed plumber replaces a flexi hose, they will typically:
- Isolate the water supply at the isolating valve or toby
- Drain residual water from the line
- Disconnect the old hose from both the tap/mixer and the supply valve
- Inspect the valve and tap connections for wear
- Install a new, correctly rated flexi hose with appropriate thread tape or fittings
- Restore water supply and check for leaks
- Issue a Certificate of Compliance for the work (required for restricted plumbing work)
The Certificate of Compliance is an important document — keep it with your home records. It confirms the work was done to the NZ Building Code standard.
Choosing the Right Replacement Hose
If you're buying the hose ahead of time for your plumber, look for:
- 304 or 316 stainless-steel braiding (316 is more corrosion-resistant, better for coastal NZ homes)
- Correct length and thread size to match your existing fittings (your plumber can advise)
- A hose rated to at least 1,500 kPa working pressure
- Products available from Bunnings, Mitre 10, or PlaceMakers
Always follow the manufacturer's installation instructions, which your plumber will do as part of the job.
Cost Guide (Approximate)
As a rough guide only, a licensed plumber replacing one or two flexi hoses under a vanity typically takes less than an hour. Plumber call-out and labour rates vary around NZ, so get a quote from a local tradesperson. The hoses themselves are generally modest in cost. Combining the job with other small plumbing tasks can make the call-out fee more economical.
When to Call a Professional
Call a licensed plumber if you:
- Notice any sign of hose wear, corrosion, or leaking
- Have hoses that are more than 5–10 years old
- Are renovating your bathroom and want hoses replaced as part of the work
- Have experienced a hose failure and need emergency repairs
You can find qualified, local licensed plumbers on tradedirectory.co.nz. Always confirm your plumber is registered with the PGDB before work begins — you can search their register online.
Safety note: If a flexi hose bursts while you're home, immediately turn off the toby (main water supply stopcock, usually near the boundary or under the house), then call a licensed plumber. If water is near electrical fittings or appliances, turn off the relevant circuit at your switchboard and contact an electrician registered with the Electrical Workers Registration Board (EWRB).
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