They can be found in kitchens, utility rooms, or bathrooms. Mixer taps are easy to install and use. However, if you notice your mixer tap leaking from the base it could be due to several factors: improperly installed seals on the base of the fixture; corrosion of internal parts; faulty construction; or excessive wear and tear over time. The following section will discuss possible causes for this type of leak, as well as how to fix it!

Mixer Tap

What is a Mixer Tap?

A mixer tap is a tap that combines cold and hot water into one steady stream. A mixer tap allows you more control of the water temperature as you are able to adjust the flow of the hot and cold inputs until you get the desired temperature output. These days there are all sorts of different shapes and sizes of mixer taps. Some of them are rigid and do not move once fitted and others will swivel from left to right. You can of course now get pull-out spray mixers too which are becoming increasingly popular. These are designed to be even more flexible with a flexible hose that can be moved around and pointed in any direction.

These have been around for quite some time in commercial kitchens and restaurants, but many people are now having them in their homes.

Why is my Mixer Tap Leaking from the Base?

There are many reasons why a mixer tap will leak from the base; cheap materials, poorly sealed joints, and degradation from old age can all be major causes of this problem. There are 2 possible types of leaks here. The first leak is where there is visible water appearing at the base of the mixer tap and the second type of leak is where there is water appearing from the base below the sink inside the cupboard.

Luckily, both of these types of leaks are easily recognisable and can be fixed quickly.

Leak 1 – Above the Sink

This is the type of leak where many people get themselves confused as in most cases; the water is not coming from the base. Although at first glance it may look like the water is coming from the base, the water is likely just pooling there and is actually coming from the swivel joint above.

Leak 2 – Below the Sink

This type of leak is where water may appear inside the cupboard below with no visible degradation in any of the actual plumbing or pipework.

This could be an indication that the leak is not actually from the pipe system but is leaking through from above where the poorly sealed tap meets the sink.

How to Find the Leak?

Turn the tap off, dry the area thoroughly as best you can and then hold some kitchen paper around the base of the mixer tap. By doing this, when you turn the tap back on, you should immediately see which part of the paper becomes wet first which will show you where the water is coming from. If there is a little water occasionally pooling inside of your cupboard, this could indicate that the tap is not seated correctly and creating a good enough seal with the sink. This can be caused by taps that have not been fitted correctly or have been knocked out of place.

To fix this, it will be a good idea to loosen the taps from underneath the sink and re-seat them. If the washer has degraded and is unusable, you may want to use a little putty such as Plumber’s mait. If, however, the leak appears at the base of your mixer tap above the sink, one of the easiest ways to see where the leak is coming from is with some kitchen roll.

Leaking Mixer Tap
Leaking Mixer Tap

How to Fix a Mixer Tap Leaking from the Base?

If you have managed to find the source of the leak and you have found that the water is coming from the swivel, next up is the fun part – for some of us anyway. It is time to strip down the tap and see if we can fix the issue that we have been having.

Step 1 – Turn off the Water

To get started, you need to turn off the water first. This is usually done by turning the water isolation valves located under the sink. Once you have turned the valves, run the tap for a second or two until the water has stopped flowing.

Step 2 – Remove the Cap

The cap is the uppermost part of the tap, usually, the part that you turn to make the water turn on/ off. There are so many different types of taps that you will need to figure this part out for yourself.

I have had taps in the past that have had screws holding the head in place, others just lifted off and the ones I have now have a grub screw that requires an Allen key.

Step 3 – Remove the Shroud

If you are lucky, the shroud may only be hand-tight but if the tap is quite old, this may be stuck in place. If the shroud is stuck in place, you can use a pair of grips to remove it. If you intend on keeping your taps, you may want to wrap something around the tap to prevent them from being scratched – alternately, you can use a strap wrench which will also help you loosen the shroud without causing any damage.

Step 4 – Undo the Nut

Using a large adjustable spanner, you will now need to undo the nut. This nut is what is holding the mixing cartridge in place. Once you have undone the nut, you will be able to remove the cartridge.

Step 5 – Remove the Cartridge Casing

This part is usually a little more difficult and this part of the tap is quite stubborn. I recommend that you use a strap wrench to prevent damaging the cartridge housing itself.

Step 6 – Check the Swivel Washer

Below the cartridge housing, there should be a washer. This washer is particularly important as this is meant to provide a watertight seal to the tap and prevent any leakage. If the washer is still in good condition albeit a little grubby, it should still be usable. Remove the washer and give the area a good clean with a wire brush to remove any dirt and build-up that could be stopping the washer from doing its job.

If the washer is damaged or broken, this will need replacing. Getting the correct washer may be a little difficult but if you take the washer to your local plumber’s merchant, hopefully, they will have a replacement.

Step 7 – Put the Tap Back Together

Next, you will want to put the tap back together. You will want to complete the same steps as before but in reverse, although you will want to ensure that you are seating the washer at the swivel correctly or you may still end up with a leak.

Step 8 – Test

Once, you are happy that the washer has been seated correctly and the tap is back together, you can turn the isolation valves back on and test the tap to see if your problem has been resolved.


In almost all cases of mixer taps leaking at the base is down to either a build-up of dirt or damaged or degraded washers at the swivel joint. Luckily, these problems are quite easy to fix provided you have a little time and patience to strip the tap down and put it back together again.

Why is my Mixer Tap Leaking from the Base Infographic

Plumbing Wizard Tips

“If you have chrome taps, use a strap wrench or cover the tap with a cloth to prevent scratches!”

“Remember to turn the water off before you start taking the tap apart – unless you want to get yourself and your house soaking wet that is!”

“You can buy O-ring kits and washers in packs but for a specific like-for-like replacement, it is better to visit a plumber’s merchant!”

“Use kitchen roll to identify where the leak is coming from – this will help you identify the location of the fault that needs attention!”

Frequently Asked Questions

Why does my tap leak at the base?

There are a couple of primary reasons why a tap may leak at the base. The first reason is that there might be dirt or another build-up that has unseated the washer meaning that the tap is no longer watertight.

Another possible cause might be that one of these washers (O-rings) has broken and needs replacing.

How do I change an O ring on a mixer tap?

  • Turn off the water supply and remove the retaining nut using a spanner.
  • Remove the shaft from the body and clean it with a degreaser or strong soap solution.
    Dry thoroughly.
  • Insert the O-ring into the groove for the top lever first before inserting it in the grooves for the handle lever.
  • Ensure the fit is snug but not excessive.
  • Replace the shaft, ensuring that there are no gaps between washers/gaskets at the upper end of the shaft.
  • Slide the retaining nut onto the shaft and tighten it firmly with the spanner before turning on the water supply to test for leaks.
  • Repeat if needed, tightening by half-turns, until there are no gaps between washers/gaskets at the upper end of the shaft or a leak appears from under the bottom lever.

How do I find the Leak on my mixer tap?

The best and most efficient way to find where the leak is coming from on a mixer tap is to use kitchen paper. Dry the area as best you can and then wrap some dry kitchen paper around the tap until you are able to see which part is becoming wet first.

How can I prevent scratches when working on the tap?

To prevent scratches, especially on chrome taps, use a strap wrench, cover the tap with a cloth, or wrap something protective around it.

Where can I find replacement washers or O-rings for my mixer tap?

You can purchase O-ring kits and washers in packs, but for specific, like-for-like replacements, it’s advisable to visit a plumber’s merchant. They can help you find the exact match for your tap.

Are there specific types of mixer taps that are more prone to leaks?

All mixer taps, irrespective of their design, can develop leaks over time. However, the causes might differ based on the materials, construction quality, and usage frequency.

What Does a swivel washer do in a mixer tap?

The swivel washer in a mixer tap provides a watertight seal to prevent leakage. If it’s damaged or degraded, it’s a common reason for leaks at the base of the tap.

Is it always necessary to replace a degraded washer, or can it be repaired?

If a washer is slightly dirty but still in good condition, it can be cleaned and reused. However, if it looks worn, damaged or broken, it’s best to replace it to ensure a watertight seal.

If I’m unsure about the exact washer or O-ring size for my mixer tap, what should I do?

Taking the old washer or O-ring to a local plumber’s merchant can help. They can guide you to find the exact or closest match for your tap.

How often should I inspect or service my mixer tap to prevent potential leaks?

Regularly checking your tap for signs of wear and tear can prevent sudden leaks. Depending on usage, a general inspection once a year might be a good practice.

Can I use any type of putty to seal the tap base if the washer is degraded?

No, if a washer has degraded, it will need replacing. Using plumber’s putty will not be sufficient to seal moving parts.

Are pull-out spray mixers more challenging to fix than standard mixer taps?

Pull-out spray mixers have added flexibility and components, which might require additional steps or considerations when fixing. However, the fundamental troubleshooting methods remain the same.

Can mixer tap leaks lead to larger plumbing issues if left unattended?

Persistent leaks can cause water damage, mould growth, or corrosion over time. It’s essential to address any leak promptly to prevent more significant issues.

Are there any telltale signs of a mixer tap nearing the end of its lifespan?

Frequent leaks, rust, difficulty in turning, and reduced water flow are some signs that your mixer tap might need replacement.


Lee Pearce is not just a master plumber; he’s a veritable Plumbing Wizard. With over 30 years of experience in the trenches of pipes and drains, Lee has become the go-to sage for DIY plumbing, saving homeowners thousands in potential call-out charges. As the founder of Plumbing Wizard, he’s dedicated to demystifying the complexities of home plumbing, offering easy-to-follow advice that stands the test of time and pressure. His online blog is a treasure trove of tips, tricks, and tutorials that empower everyday individuals to take charge of their home’s plumbing health. Lee’s practical wisdom is not just about fixing leaks; it’s about imparting confidence and self-reliance. When he’s not writing or elbow-deep in a plumbing project, Lee is passionate about educating the next generation of DIYers, ensuring that practical skills are passed down and preserved.

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