How to Tell If Your Home Has Dux Quest Pipes (a 5-Minute Check)
Was your home built — or replumbed — between the late 1970s and the mid 1980s?
If so, there's a reasonable chance the pipes behind your walls are Dux Quest. You don't need to panic. But you do need to know what's installed, because it changes how you plan maintenance, renovations and insurance.
Here's how to check in about five minutes, without opening a single wall.
What Dux Quest actually is
Dux Quest — often branded Dux Qest on the pipe itself — is a New Zealand-made polybutylene plastic pipe, installed in tens of thousands of Kiwi homes from around 1978 until the mid 1980s, when it was withdrawn.
The failure pattern is well established by now. The grey acetal plastic fittings — the elbows, tees and joiners — went first, which is why so many early Dux Quest leaks appeared at the joints. Decades on, the pipe itself is reaching the end of its life too.
What speeds it up: chlorinated town supply attacks the plastic from the inside, and higher hot water temperatures and pressures accelerate the ageing. An Auckland home on mains-pressure hot water is asking more of a 45-year-old plastic pipe every single day.
And because these failures usually start as slow weeps inside walls rather than one dramatic burst, the damage is often well underway before anyone sees it. The earlier it's identified, the more options you have.
Where to look
You can usually see exposed pipework in a few spots:
The hot water cylinder cupboard — the most reliable place to check
Under the kitchen sink and the laundry tub
The subfloor or ceiling space, if you have safe access
What you're looking for
Grey or black plastic pipe (Dux Quest is most often grey; black was also produced)
The word DUX, Dux Quest or Dux Qest printed along the pipe — the lettering can fade after four decades, so look closely
Grey plastic fittings at the joints, rather than brass or copper
Copper pipe is metallic and rigid. Modern PEX is usually a colour-coded flexible plastic. If what you're looking at is grey plastic from the right era, it's worth confirming.
Not sure? Send us a photo
Take a clear photo of the pipe — including any printing on it — and send it to us. We'll identify it free of charge, no visit needed. There's more on how that works on our Dux Quest pipe replacement page.
Why check now rather than later
Experience has taught us that homeowners who identify Dux Quest early get to make decisions on their own timeline — a planned replacement, staged around renovations, at a quoted price. Homeowners who find out during a leak make the same decisions under pressure, with wet carpet, opened walls and an insurance claim in play — and a hidden leak that's been weeping for months often lands on the gradual-damage side of a policy, where cover is thinnest.
If you're seeing signs of a hidden leak already — damp patches, a water bill creeping up, the sound of running water — start with leak detection and we'll tell you exactly what we find.
Five minutes with a torch today beats a wet wall in winter.
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