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Everything You Need To Know About Leaking Compression Fittings (And How To Fix Them)

Got leaking compression fittings? Here’s everything you need to know about what could be causing it, and how you can fix them!

Compression fittings are an essential part of every plumbing system, and they’re much more important than you realise.

Comprised of three main parts (the compression seat, a nut and a ring), a compression fitting joins two pipes together, or connects a pipe directly to a water fixture.

Without them, we wouldn’t have a safe, reliable, and easily accessible water supply, which, as you can imagine, would be a nightmare.

It isn’t uncommon for compression fittings to leak every now and again, and in this post, our experts at Total Pipes explain everything you need to know about leaking compression fittings – including possible causes and how you can fix them!

So, what causes leaking compression fittings?

There are many things that could be causing leaky compression fittings, including:

  • Incorrect use

Compression fittings should only be used on stationary connections, which means that the pipes or fixtures they’re connected to shouldn’t move back or forth in any way. Attaching compression fittings to moving pipes or fixtures can easily disturb the connection, thus leading to leaks.

  • Improper installation

When installing your compression fitting, take care to insert it completely into the pipe or fixture. This will help establish a fully sealed and secure connection to the water supply. If the fitting isn’t positioned correctly, you’re guaranteed to have a future leak on your hands.

You should also make sure not to overtighten a compression fitting as this can also cause leaks.

Assembling and installing compression fittings is simple, and can be done in a few simple steps.

First, make sure the pipe or tubing ends are clean and smooth before sliding the compression nut onto it, followed by the compression ring.

Then, insert the pipe into the compression fitting’s body until you reach the desired depth and after you’ve done this, tighten the compression nut so that it fits snugly onto the body.

Finally, turn on the water to test for any loose connections and leaks, and make any adjustments if necessary.

  • Excessive pressure

If compression fittings are put under high amounts of pressure, they’re likely to leak. Especially if the connection is on an angle.

Plasson compression fittings, however, like the ones we supply at Total Pipes, are designed to handle high strain and prevent leaks by distributing pressure evenly across fittings. Making them ideal if you need to establish a connection at a particularly tricky angle

  • Pipe issues

As we’ve previously mentioned, ensuring that the pipe you’ll be connecting has a smooth, clean opening, is essential for a secure reliable water connection.

Rough edges make it difficult to tighten the fitting, leading to leaks down the line, so it’s vital to make sure the pipe has a clean straight cut.

How can I stop leaking compression fittings?

The best way to fix leaky compression fittings, most professionals would agree, is to loosen and retighten the compression nut to help break up any corrosion on the nut threads and create a tighter seal.

Before you do this, turn off the water at the mains and make sure you have a bucket and towel close by to catch any water that may leak whilst you attempt to loosen the nut.

Once you've retightened the nut, switch your water back on to see if this has solved the problem.

If the fitting is still leaking, you more than likely need to replace it, which luckily, is a quick and easy job.

All you need to do is take apart the old fitting – using a wrench to loosen the nut and detach the body –, assemble the new one and install it in the same way using the steps listed above.

Need more expert advice?

Leaking compression fittings can wreak havoc on your plumbing system, and not only can they be a huge inconvenience, but they can end up an expensive issue if they’re not fixed right away.

Whether you’re in need of additional advice, or searching for somewhere to buy top-quality plasson compression fittings, Total Pipes is the company to call.

To find out more about installation, maintenance and repairs, or for more information about our products, give us a call today on 01254 382 000 or email us at and we’ll be in touch to answer your questions!