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How To Fix a Leaking ProPress Fitting? Step-By-Step Instructions

ProPress fittings are a reliable option for many types of plumbing systems as they can endure extreme temperatures. Even better, the fittings are easy and relatively inexpensive to install over traditional pipe-joining methods like soldering and brazing. Despite their reliability, these fittings are susceptible to leaks.

But how do you fix a leaking ProPress fitting? To fix a leaking ProPress fitting, you can try repressing it for a tighter connection. If this does not help repair the leak, you can change the O-rings if they are damaged or missing. Alternatively, you can replace or reinstall the ProPress fitting where the leak is severe.

Now you might wonder, what causes the ProPress fitting to leak? Below we will discuss the different methods of fixing a leaking ProPress fitting and the mistakes to avoid.

What Causes ProPress Fittings Leak?

Despite their reliability and durability, these fittings may leak. Below we will discuss the causes of the leaks.

Improper Installation

During the installation, the fitting must be pressed into the pipe to create a secure seal. If you skip this step or use misaligned pressing jaws to do the pressing, the fitting may leak.

Worn Out ProPress Fittings

While the ProPress fittings are made with durability in mind, they may wear out or get damaged over time. This may happen due to exposure to harsh environments, age, or improper installation, leading to leaks.

Incorrect Size Fitting

ProPress fittings come in hundreds of configurations and sizes that range from 1/2” to 4”. If you choose the wrong sizing, the fitting will remain loose and leak. 

Missing or Damaged Internal O-rings

The pressing process only locks the tubing into the ProPress fitting. What makes the secure seal are the O-rings. So, if the O-rings go missing or become damaged, a leak is likely to occur over time.

Failing to Insert Pipes into Depth

If the pipes don’t reach the depth of the ProPress fitting properly, this could lead to leaks. This is because, over time, the fittings would begin loosening and becoming slack.

Signs of a Leaking ProPress Fitting

If you suspect your ProPress fitting is leaking, you can confirm this by looking for the following signs.


Any staining or discoloration on the walls, floors, or ceilings may be a sign of a leak in the fitting. You may also notice a green stain where the tubing enters the fitting.


Sometimes, you may observe a slow drip around the fitting. This may occur immediately after the installation or over time.

Decreased Water Pressure

If you turn on a shower or faucet and notice a drop in water pressure, it could be a sign of a leak in the plumbing system.

High Water Bills

Another indicator of a leak in your ProPress fitting is a sudden increase in your water bills. However, the leak could be anywhere in your plumbing system.

How To Fix a Leaking ProPress Fitting?

how to fix a leaking propress fitting

Depending on the location and severity of the leak in your ProPress fitting, there exist 3 primary methods for fixing it. Let’s check them out.

Method 1: Repress the Fitting

This method works best when the leak is small or is a result of a slow drip. However, if you have pressed the fitting before, you cannot repress from the same orientation. Repressing helps restore the fitting’s secure seal.

The method would also work if the fitting was never pressed.

  1. You just need to ensure the copper or metal tubing is properly installed and press the fitting.
  2. Then, use a ProPress power tool to tighten the fitting.

Method 2: Change the O-rings

If the leak is due to missing or damaged O-rings, you must replace them immediately. Here is how to do it.

Step 1: Turn off your water supply and release pressure inside the pipe by turning on a faucet.

Step 2: Cut the metal or copper pipe on both ends of the fitting using a saw.

Step 3: Use a ProPress tool to loosen the fitting from the pipe and pull it out.

Step 4: Remove the old and damaged O-rings from the ProPress fitting using a small screwdriver or pliers.

Step 5: Install the new O-rings on both sides of the fitting and ensure they are seated properly.

Step 6: Slide the ProPress fitting back onto the pipe. Then, use a press tool to tighten it and turn on the water supply. 

Method 3: Replace or Reinstall the Fitting 

If the fitting is damaged or you installed it incorrectly by not pressing it, you can replace or reinstall it. This method is ideal when the leak is severe and repressing the fitting is not an option. Following are step-by-step instructions on how to do it.

Step 1: Locate your leaking ProPress fitting and turn off the water supply.

Step 2: Cut the pipe a little back from the fitting and remove the leaking fitting.

Step 3: Clean any remaining residue or debris from the pipe.

Step 4: Slide in a new ProPress fitting onto the pipe’s end and use the ProPress tool to secure it. Make sure the fitting is of the correct size.

Step 5: Once done, you can install an in-line ProPress coupling to heal the cut pipe.

Common Mistakes to Avoid When Fixing a Leaking ProPress Fitting

When fixing a leak in your ProPress fittings, there are various mistakes you must avoid to prevent expensive repairs. These include:

  • Over-tightening the fitting when repressing it. This could damage the pipe or the fitting itself
  • Failing to align the pressing jaws of the ProPress tool properly before using it to repress the fitting
  • Using the wrong size ProPress fitting or tool
  • Repressing the fitting more than once on the same orientation and with the flats not aligned. This could cause the joint to come apart
  • Installing the ProPress fitting with missing parts like O-rings, leads to improper connections


Before we conclude, let’s quickly check out some frequently asked questions regarding ProPress fittings leaks and failures.

Q: Can you solder or braze a leaking ProPress fitting to fix it?

No, it is not recommended. The heat generated during the soldering or brazing process can damage the fitting and the O-ring. As such, the leak will continue instead of stopping. However, you can solder or braze near ProPress fittings.

Q: Can you repress a ProPress fitting?

Yes, but only under certain circumstances. These include if the fittings and the O-rings are not damaged. Also, repressing is possible if the leak is minor.

Q: How long do ProPress fittings last?

When properly installed, these fittings may last over 25 years. This explains why some manufacturers like Viega offer a 25-year warranty on their ProPress fittings against material defects.

Bottom Line

Propress fittings can connect to any copper or metal pipes, ensuring a secure and leak-free connection. However, due to improper installation or using incorrect size fittings, a leak may occur. And you can tell if your ProPress fitting has a leak by looking out for discoloration or reduced water pressure.

Luckily, it is possible to fix a leaking ProPress fitting by repressing it, changing the O-rings, or replacing the fitting. But while repairing the leak, there are several mistakes to avoid, like overtightening the fitting.