How to fix a leaking tap, everything you need to know

You may think that a leaking tap is nothing more than a nuisance that keeps you up at night, but it can cause severe damage to your home. Learning how to fix a leaking tap can save you thousands of litres of water in a year and save money in the process.

What is the common cause of a leaking tap?

Here’s a surprising fact, the number one cause of leaking taps is not the washer but the valve seat that stops the water from flowing when the tap is closed.

Our handy guide will guide you through how to fix a dripping tap, whether it’s your first attempt or you need a refresher.

The tools for the job

Before you get down and dirty, or in this case wet, make sure that you have the following tools:

• A pair of scissors
• An adjustable spanner
• O-rings, washers (12mm washers are common in homes), and a replacement cartridge
• Jumper valve
• Screwdriver
• Reseating kit
• Tap spanner set
• Tap lubricant
• Cloth

The Procedure

Turn off the main water supply, then turn on the leaking tap until all the water runs out. To completely turn off the water, check below the tap that you are working on for an isolation valve, if you find one, turn it with a screwdriver.

If you don’t find an isolation valve, locate the stop valve and turn off the water from there.

Get a screwdriver, and unscrew the handle. If you have a modern tap, the screw is under the indicator (red and blue for hot and cold water respectively). Once you unscrew the handle, you will expose the body and spindle. If the top of the spindle has water and the outer frame is wet, then you need to change the O-ring because this is an indication that it's leaking.

Important tips

Don’t forget to plug the sinkhole before you start working on the tap. That way, you won’t lose the anything (tools or parts of the tap) down the drain. Also, secure the tap with a spout when unscrewing the handle to prevent the whole tap from turning. You might crack the sink or damage the pipework if the tap turns when unfastening.

Apply penetrating oil on any stuck nut instead of applying force.

Steps to change a leaking O-ring

• Loosen the body by unwinding it using a spanner. Remove the body washer at the base of the tap and pull out the jumper valve.

• Expose the O-ring and cut it off with a knife. 

• Wipe the jumper valve until its dry and clean then roll on a new O-ring. Roll the new O-ring on and pop the spout back in place and tighten the screw.

• Place the jumper valve back inside the body and place a new body washer on the base. Grab the tap and tighten with a spanner.

• Screw everything back in place, i.e., the cover, handle and button.

• Turn on the water from the mains and open the tap slowly to let out the air.

• Turn off the tap and check for leaks.

A worn-out washer

After exposing the body of the tap, check the washer that is next to the pin at the bottom for any damage. If the washer is in excellent condition, then it’s the valve seat that’s causing the leak. Change the washer if it's damaged by following these steps:

Using an adjustable spanner, hold and turn the valve until it’s loose enough to be removed by hand.

Slide or unscrew the worn-out rubber washer and replace it with a new one. If you’re struggling to get the new washer over the pin, apply some petroleum jelly and slide it using a spanner or the side of your pliers.

Tighten the valve back in place and put everything back together.

A leaking tap valve

If your tap is continuously dripping, the problem might be the valve seat. Water might force itself under the washer and erode the brass that holds the seat. Small canals form in the seat and allow water to pass the washer and straight through the tap. Hard water is the leading cause of a leaking tap valve.

• Remove the tap valve.
• Once you have the tool in hand, insert a grinder, tighten it up and then push it up and down the handle and don’t forget to twist. This process makes the seat grinder smooth. 
• After a few turns, remove the grinder and run your fingers around the top of the seat to check for indents. 
• Keep grinding until the valve seat is entirely smooth.
• Put everything back in place and turn on the water. 

Important tip: apply tap lubricant to the valve and spindle for better sealing and tap operation and do not overtighten the nuts when refitting the bonnet and spindle.

How to fix different types of leaking taps

Your tap uses a washer or a ceramic disc. The only way to know the type of tap you have is to give it a turn. If the tap rotates half or quarter of the way, then it’s a ceramic tap. If you can turn the tap more than halfway, then it's traditional. A worn-out O-ring is the primary cause of leaks in traditional taps. If the tap is still leaking even after replacing the washer, you need to check the state of the O-ring. 

How to fix a dripping mixer tap

Mixer taps come in different designs, but the common ones consist of two taps connected to one central spout. The procedure of fixing this type of mixer tap is similar to single taps, but you need to find the one that's dripping.

How do you do this?

Turn off each tap and check the one that stops the leak. You can fix the mixer tap without turning off the water supply but only if the unit has separate O-ring seals at the bottom area of the spout.

How to fix washerless taps

A washerless tap, as the name suggests, does not have a washer but a mixer function and rotating handles that control the temperature and flow of water.

Washerless taps are low maintenance, but some of the parts can malfunction. Check the manual to know how to dismantle the part and fix problematic areas.

If you don’t have a manual, do not attempt to DIY to avoid severe water leakage. Call a plumber and see how they do it; if you are a handy person, you will learn how to do it next time.

How to turn off the water

Most Australian homes have water meters located above ground, and the stop valve is usually a tap. Remember that any plumbing task that is beyond replacing washers, tap valves and O-rings should be left to the professionals.

Homeowners are not allowed to work on any system directly connected to the main water supply or sewer system.

This rule is in place to prevent tampering of the water supply system. Check with the local authority before taking up any plumbing work.

Call the professionals

Fixing a leaking tap requires time, dedication and skills. You can use the information in this article to fix a dripping tap, but if you don’t have the time or its too much work for you, then it’s time to look for plumbing services near you. A plumber has the skills and experience to fix any problem that’s causing a leak in no time.