How to Fix a Tap That Spins But Won't Turn Off the Water

A tap that just keeps spinning without shutting off the water is one of the most common plumbing problems in NZ homes. In most cases, the fix is straightforward — a worn jumper valve (also called a tap washer) or a stripped spindle is usually to blame. With the right parts and a bit of patience, many homeowners can tackle this repair themselves.

Why Does a Tap Spin Without Stopping the Water?

Traditional pillar taps and mixer taps with ceramic or rubber washers work by pressing a washer down onto a seat to stop water flow. When the tap spins freely, it usually means one of the following:

• The jumper valve or washer has worn out and is no longer seating properly
• The spindle thread is stripped, so turning the handle no longer moves the spindle up and down
• The tap seat is damaged or corroded, preventing a proper seal even with a new washer
• On older taps, the grub screw holding the handle to the spindle has come loose

Identifying which part has failed will tell you what to replace.

What You'll Need

• Adjustable spanner or basin wrench
• Flathead and Phillips screwdrivers
• Replacement jumper valve/washer kit (available at Bunnings or Mitre 10)
• Tap reseating tool (if the seat is damaged — hire or buy from most hardware stores)
• Plumber's grease (silicone-based)
• Old towels or a bucket

Step 1 — Turn Off the Water Supply

Before you do anything else, isolate the water supply. Look for an isolating valve under the sink or basin — turn it clockwise to close it. If there's no isolating valve, you'll need to turn off the water at the toby (main stopcock), usually located near the boundary of your property.

Once isolated, open the tap fully to release any pressure and drain remaining water from the line.

Safety note: Never work on a tap without first confirming the water is fully off. Have towels and a bucket ready in case of residual water.

Step 2 — Disassemble the Tap

1. Remove the tap handle — there's usually a decorative cap on top hiding a screw. Pop the cap off with a flathead screwdriver and undo the screw beneath.
2. Lift the handle off. If it's stuck, gently wiggle it — don't force it.
3. Use an adjustable spanner to unscrew the packing nut (the large hexagonal nut below the handle).
4. Pull the spindle straight up and out of the tap body.

Step 3 — Inspect and Replace the Jumper Valve

At the bottom of the spindle you'll find the jumper valve — a small disc with a rubber washer. Check it for:

• Cracking, hardening, or deformation of the rubber
• The jumper valve spinning freely (it should be retained but able to rotate slightly)
• A completely missing or disintegrated washer

If the washer is worn, simply replace the jumper valve assembly. These are inexpensive and widely available. Make sure you match the size — most NZ household taps use a standard 12 mm or 15 mm jumper valve, but check your existing one to be sure.

Also inspect the spindle thread. If the thread is stripped or the spindle wobbles loosely, the spindle itself needs replacing. Take the old one to your hardware store to match it up.

Step 4 — Check the Tap Seat

With the spindle removed, shine a torch into the tap body and look at the seat — the ring the washer presses against. If it looks pitted, grooved, or corroded, a new washer alone won't fix the problem. You'll need to:

• Use a tap reseating tool to grind the seat smooth, or
• Replace the entire tap (often the more practical option on older taps)

Step 5 — Reassemble and Test

1. Apply a small amount of plumber's (silicone) grease to the spindle thread.
2. Reinsert the spindle, hand-tighten the packing nut, then snug it up with the spanner — don't overtighten.
3. Refit the handle and screw.
4. Slowly turn the water supply back on and test the tap. It should now turn off firmly without spinning.

Ceramic Disc Taps — A Different Story

Many modern mixer taps use a ceramic disc cartridge rather than a rubber washer. If your tap has a single lever or a quarter-turn action, it likely has a ceramic cartridge. These don't use jumper valves — instead, the entire cartridge is replaced as a unit. Cartridges are brand-specific, so note the tap brand and take the old cartridge to PlaceMakers or a plumbing merchant to find the right match.

When to Call a Professional

While replacing a washer or cartridge is generally considered non-restricted maintenance work that a competent homeowner can do, there are situations where you should call a licensed plumber:

• You can't locate or operate the toby/isolating valve
• The tap body or pipework is corroded or leaking
• The tap seat is badly damaged and you're not confident using a reseating tool
• You're working on hot water cylinder valves, tempering valves, or any gas-related fittings — these are restricted work under NZ law and must be carried out by a licensed tradesperson registered with the Plumbers, Gasfitters and Drainlayers Board
• The tap is part of a backflow prevention or pressure-limiting valve assembly

For peace of mind, you can find qualified local plumbers on tradedirectory.co.nz.

Sources & Further Reading

• Plumbers, Gasfitters and Drainlayers Board — Licensed Work
• MBIE Building Performance — Plumbing and Drainage
• BRANZ — Home Maintenance Guidance
• Bunnings — Tap Washers and Plumbing Supplies
• Mitre 10 — Plumbing Parts