Fixing a copper union fitting leaking can be tricky and tiresome. Like the piping network, copper unions can leak as well. Impure or ‘hard water’, rust particles, improper installation, etc all can cause copper unions to leak. To stop leaking, you can reseal the unions with a wrench.
Plumbers use copper union joints in steel pipelines for many reasons. Copper union joints enable the pipes to be removed when they get damaged or corroded.
Let’s talk about how we can fix leaking in copper unions.
Copper Union Fitting Leaking- Reasons with Fixes
Let’s start with a table summarizing the reasons and what we can do to fix copper union leaking:
|Reasons For leaking||What To Do To Prevent Leaking|
|Improper installation||Refitting the copper union and reapplying Teflon|
|Corrosion by impure or hard water||Replacement and/or reapplying of Teflon|
|Electrolysis||Applying Teflon and/or installing dielectric connectors|
|Excessive use of flux while installing||Apply Teflon, reseal, and/or replacement|
|Rust particles||Checking and/or replacing the water heater.|
Let’s talk more about how to stop copper union fitting from leaking.
Refitting The Copper Union
Improper installation of the fitting is one of the main reasons for leaking through copper unions. You can fix it by refitting the union if you think you have some DIY tricks up your sleeves.
The copper union usually has two female-threaded end nuts. Then there is the central nut holding the end nuts with pipe-threading.
To fix the leaking copper union fitting, you need to remove the copper union to check if it’s damaged beyond repair. If that’s the case, no matter how perfect the fitting of the Copper union is, water will leak. But if the union and nuts are ok, refitting the union will stop leaking.
To do any repairing involving supplying anything to your house, you should start by turning off the primary valve that shuts off the supply.
A copper union refitting job will need you to remove the union first.
- In the central nut that holds the union, you need to place a pipe-wrench around it. Loosen the nut by turning the handle of the wrench counter-clockwise. Then remove it from the attaching threads of one of the end nuts of the union. To prevent it from getting lost, slide the central nut along the pipe a few inches back.
- Wrap the wrench again around the closest nut to the central nut. After removing it from one end of the pipe, clean the threads of the pipe using a steel brush. Also, remove all the sealing tapes.
- When the threads are clean and free from old tapes, use new white-colored tapes for wrapping the threads clockwise. Do the wrapping at least twice.
- Use your hand to screw the end nut back onto the pipe and tighten it with the wrench.
- Do the same for the other nut as well.
- Clean the threads off from old tapes where the central nut sits. Again do the wrapping twice in the thread.
- Now put the central holding nut in its place first. Using a wrench, seal them by tightening hard, but not so hard that the threads may get broken.
- Do the same for the end nuts as well.
Hopefully, the leaking will stop now.
Fix the Leak by Reapplying Teflon
Joints relying on threaded fittings can leak when Teflon tape sealing on copper union is not done properly.
Professional plumbers use both Teflon and a thin layer of Teflon compound over the Teflon wrapping to seal the union joints properly.
Let’s have a go at it.
- As we have mentioned, you have to remove the union first and unscrew the three nuts.
- Clear out the rusts and old tapes from the threads of all the 3 nuts.
- Wrap the threads with Teflon tape. Two layers usually are enough. But if the union is old and corrosion seems to take place, you may want to wrap 6-7 times.
- Stretch the tape and tear it at the end.
- To make the sealing completely leak-proof, disperse a layer of thin Teflon compound over the Teflon tape that you just have finished wrapping.
- You have to wipe the excess compound away before tightening the nuts to complete resealing of the copper union fitting.
Protection From Electrolysis
Electrolysis occurs when the copper union gets in touch with galvanized steel piping. It eats away the metals gradually and causes leaking.
- Proper application of Teflon is the first step to preventing that.
- You can also use dielectric connectors that are made of brass. These connectors will insulate the steel from copper union fittings and prevent electrolysis.
Protecting Leaks From Flux
Flux is a kind of gel that plumbers use during installation. The compound dissolves when they get into contact with hot water. But cold water can’t do that, and residues can be deposited in time and create pinhole leaking in copper union fitting.
Master plumbers know this and are careful in using gels. If you do the renovation of any kind, remind the plumbers to be economical in using gels.
Reapplying Teflon and Teflon compounds can prevent this type of leaking also.
Protection From Rust Particles
If you have an old and rusty heating system, iron and steel particles can cause corrosion. This type of corrosion normally happens in horizontal pipes. But the deposits can cause leaking in copper fittings as well.
If reapplying Teflon and Teflon compounds can’t stop leaking, you need to replace the fittings.
This Video Will Help You Too!
Frequently Asked Questions (FAQs)
How do you seal a leaking union?
You can seal a leaking union either by refitting the central holding nut and the two other nuts that connect the union to the pipes. Before sealing, you need to remove the nuts, clean old tapes and tighten the nuts back again using a wrench.
How do you stop a copper union fitting from leaking?
You can stop a copper union fitting from leaking by sealing or reapplying Teflon. If they can’t stop leaking, you need to replace the copper union.
Do I need Teflon tape on unions?
Yes, you need Teflon taps on copper unions. Teflon prevents water from leaking through the threads. They also protect the threads from breaking down. That makes the opening of the nuts easier for repair works.
The experienced plumbers will tell you that the best way to prevent leaking is to prevent it from happening. But copper union fitting leaking also occurs from time to time and needs to be dealt with.
Refitting and resealing will stop leaking waters from copper unions in most cases. You can apply the above methods if you are confident in following instructions and have some experience in doing things on your own.
But in some cases, it’s also important to remember that taking help from professionals can actually save you some money.
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