Mixer Tap Not Working? Here’s Why

Should your tap suddenly stop or develop issues, your mind is likely flooded with worst-case scenarios. What if I have a burst pipe? Did I forget to pay the water bill? Are my pipes frozen? There are countless things that could theoretically go wrong, Luckily, if your mixer tap is not working, we’ve got a good list of the most likely culprits. And don’t worry – most of them are pretty benign.

The most common causes of a mixer tap not working are airlocks, the water main, and a failed O-ring.

Let’s talk cause and effect for a bit, and we’ll have your mixer tap sorted in no time.

Common Causes of Mixer Tap Not Working

As we mentioned above, the most common causes of a mixer tap not working are airlocks and a failed O-ring. A few other potential factors are a bumped water main, a leak, and a shutoff of service, but we’ll get to those in time.

First things first, check your water main.

Water Main

While it can be a bit embarrassing to panic only for this to be the cause, it’s a very likely one and an easy fix. Go to your water main – is it open or closed?

It’s entirely possible that someone just accidentally bumped it in passing and shut off the water to your home. This is even more likely if you were recently working on plumbing and shut if off – did you remember to put it back? Are you sure about that? If not, go look – what’s the worst that could happen?


This should be your next step. Test the other taps in your home and go talk to your neighbours – do they have running water, and do your taps work? If both answers are no, it’s likely that your provider shut off the service. Whether that’s due to a mishap with the bill, regular maintenance, or some issue along the line that needs a repair, it’s entirely possible that the issue isn’t on your end.

If the neighbours don’t have water, call your provider. They’ll be able to advise you on good next steps and help give you a guide on when to expect service to return, should this be the issue.


This is definitely the worst-case scenario, but it’s important that it’s one of the first things on your list, just in case. Begin by going to your water meter, usually located on the side (exterior) of your home.

Record the information it’s displaying, and then go turn off your water at the main. Wait an hour, and while you’re doing that, inspect the path that your plumbing takes in your home. Look for wet spots, puddles, or stains in the wall that weren’t there before. Should you notice one, call a plumber right away. If not, once the hour is up, go back to the water meter.

If your water meter’s display has changed from the number recorded previously – you’ve got a leak, my friend. And that means it’s time for the cavalry because if you didn’t spot a leak in your home, it could be beneath your home. That’s no good and can lead to all sorts of bad news down the line.


This is an incredibly common issue that’s entirely normal in plumbing. An airlock occurs when air bubbles get stuck in your plumbing and lock it up. Hence the name, airlock.

Luckily, it can be fixed in ~30 minutes with the right know-how and determination. Here’s how:

  1. Open and run all of the taps in your home. Shower, kitchen, bathroom sink – all of it. This will take up excess water, but the increased pull and pressure of that much water will often knock the airlock loose. Just run the water for a few minutes (being careful to avoid overflow) and then turn them off and see how it the tap in question works.
  2. You can also bleed your radiators.
  3. The final option is the washing machine method. It goes like this:
    1. Turn off the valves of both hot and cold water to your washing machine.
    2. Disconnect their hoses.
    3. Connect them with a hosepipe and turn on the hot water valve. Next, the cold.
    4. Leave them running for 30+ seconds.
    5. This should break the airlock pretty quickly.

And there you go – a fixed airlock, should that be the issue at hand.

O-Ring Failure

We actually just covered this! You can go on over here to see how to repair a failed O-ring, but the basic gist is as follows:

  1. Turn off the hot and cold water with the valves beneath the sink.
  2. Unscrew the spout cover/collar.
  3. Pull the cover out, looking inside.
  4. Locate the valve in the tap body, using a flashlight and phone camera if needed.
  5. Gently undo the nut holding it in place with needlenose pliers or a wrench.
  6. Pry it out, again, gently.
  7. Remove the old O-ring and replace it with a new one.
  8. Reverse the process, remembering to turn the hot and cold water back on when finished.
  9. Test your tap.

This is a super easy fix that, theoretically, you shouldn’t need a professional for. Just a new O-ring, some pliers, and ~15 minutes of your time and you should be set!

Final Thoughts

Okay, you’ve checked everything. You likely found the cause already, but if not, it’s definitely time to call the plumber. On the plus side, you did a good bit of legwork for them. That will prevent them from wasting time on these fixes, which will save you money. If it’s not an airlock, loss of service, O-ring, leak, or bumped water main, it’s likely the issue is something more complex.

Plumbing is complicated, and there are a lot of moving parts. Something as seemingly unrelated as bleeding a radiator could potentially solve a locked up tap – crazy. So if you’ve tried all of these fixes, it’s very likely that a plumber will be your best (and only) bet to get things resolved. Best case, it’s something small they can fix in an hour or two. Worst case, they catch a leak before it gets any worse.