A dripping outdoor tap might seem like a minor annoyance, but even a slow drip can waste thousands of litres of water a year — and add up on your water bill if you're on a metered supply. The good news is that many outdoor tap drips are caused by worn washers or O-rings, which are straightforward repairs most handy homeowners can tackle themselves. Here's how to diagnose the problem and fix it safely.
Understanding What's Causing the Drip
Before reaching for a spanner, it helps to know where the drip is coming from:
- Drip from the spout – Usually a worn jumper valve washer inside the tap body. This is the most common cause.
- Leak around the spindle or handle – A worn O-ring or packing around the spindle is likely to blame.
- Leak at the wall or pipe connection – This could indicate a loose fitting or cracked pipe, which may need more investigation.
Most outdoor taps in NZ are either bib taps (the classic hose tap that sticks out from the wall) or ball valves. The repair approach differs slightly between them.
Tools and Materials You'll Need
- Adjustable spanner or shifting spanner
- Flathead and Phillips screwdrivers
- Replacement tap washers (jumper valve washers) — available at Bunnings or Mitre 10
- O-ring assortment kit
- PTFE (Teflon) tape
- Silicone grease or plumber's grease
- A small container or towel to catch residual water
Washer kits are inexpensive — as a guide, a mixed pack typically costs just a few dollars and you'll find them in the plumbing aisle at most hardware stores.
Step 1: Turn Off the Water Supply
This is the most important step. Locate the isolating valve or toby (water meter) valve that controls water to the outdoor tap. Many homes have an isolating valve on the pipe just inside the wall behind the tap — turn it clockwise to close. If there's no isolating valve, you'll need to turn off the main toby at the boundary.
Once the water is off, open the tap fully to release any pressure and drain residual water from the line.
Step 2: Disassemble the Tap
- Remove the handle — usually held by a screw under a decorative cap on top. Prise off the cap with a flathead screwdriver, then undo the screw.
- Unscrew the packing nut (the large hexagonal nut below the handle) using your adjustable spanner. Turn anticlockwise.
- Pull out the spindle assembly — the washer and jumper valve are at the bottom of this.
Tip: Wrap the jaws of your spanner with tape to avoid scratching chrome fittings.
Step 3: Replace the Washer and/or O-ring
- Inspect the rubber washer at the base of the spindle. If it's cracked, hardened, or deformed, it needs replacing. Pop out the old washer (it may be held by a small brass screw) and press in a new one of the same size.
- Check the O-ring around the spindle body. If the leak was around the handle, this is your culprit. Roll the old O-ring off and replace it with a matching size from your kit. Apply a little silicone grease before fitting.
- Wrap PTFE tape around any threaded connections you've disturbed, winding it clockwise (in the direction of tightening).
Step 4: Reassemble and Test
Reassemble in reverse order — spindle in, packing nut tightened firmly (but don't overtighten or you'll crack the fitting), then the handle. Turn the water supply back on slowly and check for leaks. Open and close the tap a couple of times to seat the new washer properly.
If the tap still drips after replacing the washer, the tap seat (the brass surface the washer presses against) may be damaged or corroded. A plumber can re-grind or replace the seat.
Preventing Future Drips
- Don't overtighten outdoor taps when closing them — this wears washers faster.
- In areas that get cold winters (Central Otago, Canterbury high country, etc.), consider draining outdoor taps before a frost or fitting a frost-proof tap to prevent freeze damage.
- Check your outdoor tap annually as part of a general home maintenance routine. BRANZ has useful guidance on home maintenance schedules.
What About Ball Valve Taps?
Modern outdoor taps sometimes use a ball valve mechanism rather than a traditional washer. These are generally more durable but when they do fail, the internal cartridge or seals usually need replacing as a complete unit. The process is similar — isolate water, disassemble, replace the cartridge — but make sure you buy the correct replacement cartridge for your tap brand.
When to Call a Professional
While replacing a washer is DIY-friendly, some plumbing work in NZ is restricted work under the Plumbers, Gasfitters and Drainlayers Board (PGDB) regulations. You must use a licensed plumber if the job involves:
- Cutting into or modifying water supply pipes
- Installing a new tap or moving the tap location
- Replacing the tap body itself (which connects to the pipework)
- Any work on the hot water system
If your tap is leaking at the wall connection, the pipe is corroded or cracked, or you're simply not confident tackling the repair, it's well worth calling in a professional. A qualified plumber can sort it quickly and ensure the work complies with the NZ Building Code (particularly clause G12 – Water Supplies). You can find licensed local plumbers on tradedirectory.co.nz.
Safety note: Never attempt to work on pressurised pipes without first isolating the water supply. If you're unsure which valve controls the outdoor tap, turn off the main toby to be safe. Check with WorkSafe NZ guidelines if you're ever uncertain about safe working practices.