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Home » Water Softeners » Why Is My Water Softener Leaking?

Why Is My Water Softener Leaking?

By: Craig Smith
Last Updated:
Why Is My Water Softener Leaking?

When I moved into my first home, I went down to the basement one day and to my surprise, the floor was almost completely covered in water.

After assuming the worst, such as a pipe breaking or a washer drain had backed up, I determined the water softener leaking was the cause of the problem.

It was the first time I realized that water softeners can and do leak. If you are now experiencing something similar and wondering ‘why is my water softener leaking’, that’s something that I am prepared to help you determine.

I can do this because of my experiences with my own water softeners over the years and with my extensive swimming pool plumbing background.

Here you will learn what may be causing your water softening system to leak, how to attempt to fix it yourself, and in what situations you need to ask for professional help.  

Although the ion-exchange process water softeners use to remove unwanted calcium, magnesium, and other hard water-causing chemicals is complicated, their working components are not that difficult to diagnose and repair as far as leaks go.

Also Check Out: Water Softener Maintenance Tips

Before Diagnosing a Leaking Water Softener


Although your water softener may seem like a harmless device, remember it has a control head that is powered by an electrical connection. To diagnose a water softener leaking, you will first want to shut off the power going to it.

Do this by searching out the breaker in your electric box that controls the power that feeds you water softener. When you experience a water softener leaking, never step into large or even seemingly insignificant puddles of water that are near it unless the system’s power is off.

Remember, water is an excellent conductor of electricity!!

So, you never want to go near any leaking devices to diagnose them that have an electrical connection such as a water softener leaking or leaky water heaters, washers, and whole-house water filtration systems unless the power to them has been turned off.

Failure to do this can have severe consequences.  

Once this has been done you will next want to locate the water supply valve to your water softener. Most plumbers will hook up a water softener bypass valve into the system when they plumb in the system.

Activate this valve so water still goes to your home but not to your leaking water softener. It’s ok to turn it on and then back off a few times if you need to do this to diagnose where your water softener leak is.

Why Is My Water Softener Leaking from the Top?


You can see in the diagram above that water softeners consist of two different tanks they make use of to function properly.

On the left is the main tank (also known as a resin tank) where the ion-exchange process takes place to remove hard water-causing minerals.

On the right is what’s known as the brine tank. This tank makes a sodium chloride or potassium chloride solution that is transferred to the main tank to facilitate the ionic reaction that’s needed for water softeners to work.

Either of these two tanks may start leaking at the top.

Common Causes of Resin Tanks to Leak at the Top

Here are some of the main reasons why a water softener’s resin tank leaks at the top:

  1. Bad Rotor Valve or Bypass Valve Seal

Like any type of device that uses rubber O-rings or seals, water softeners have these too. These tend to wear down or become stretched so they no longer make a good seal which most likely will result in a water softener leaking.

This is very common with a bypass valve because of the friction that placed on an O-ring when the bypass valve is activated.

Bypass Valve Seal

Replacement seal and O-ring kits are usually available for the bypass valve on a water softener and the other seals and O-rings on it too. 

  1. Cracked Rotor Valve

A rotor valve on a water softener is usually made of rigid plastic and over time it can wear down and eventually crack. When this happens, it can result in a leak forming at the top of the main tank.

  1. Leaky Feed or Supply Side Water Line

There is a plumbing pipe that brings untreated water into the main tank and another plumbing pipe that feeds the now softened water back into the household supply. The connections on these pipes can become weak or loose over time and leak.

The Reasons Why Brine Tanks Leak at the Top

Here you have to keep in mind that a brine tank is not a closed tank that’s sealed at the top. This is because they need to be opened regularly to have salt added to them and water should never get near the top of them anyway if they are working properly.

What can happen to make them overflow? Here are a few reasons:

  1. Lack of Periodic Cleaning

As part of your water softener’s routine maintenance, you should completely empty the salt and water from it once per year to keep it clean and functioning properly.

Failure to do this can cause a salt bridge, salt clumps, and other conditions that can make your brine tank overflow.

  1. Clogged Drain Lines

It goes without saying that if the water will not drain out of your brine tank, the water level inside of it will keep rising until it eventually overflows. So keep periodically clean your salt tank to avoid a water softener leaking overflow.

  1. Defective Float Switches

To prevent your water softener’s salt tank from overflowing, there is a float switch inside of it that won’t allow any more water to go into the tank once the water level gets to a certain point. When these switches malfunction, the tank that makes the brine solution may overflow.

Why Is My Water Softener Leaking from the Bottom?

If the source of your water softener leaking is at the bottom of one of its two tanks, most likely this is due to them being cracked or punctured. 

A punctured brine tank is much more common because their tank walls are not nearly as thick and durable as the walls on the resin tank.

That’s why you need to be extremely careful when cleaning your brine tank and resist the temptation to use sharp or blunt tools to break out and remove salt clumps.    

Depending on the severity of the crack or puncture and its location, this cause of a water softener leaking may be able to be repaired.

What Causes A Water Softener Hose to Leak?


You will have a connection on your water softener that aids in the transfer of the salty water in its brine tank to the resin tank after an automatic regeneration cycle (cleaning cycle) has been performed.    

This water softener hose or line can be made out of rigid pipe, braided flex pipe, or a rubber hose material. 

These brine solution-carrying lines may also have glued, quick, or clamped connections on them. Poor connections and dried cracked hoses can eventually cause water softener leaking.

Water softener hose leaking is often caused by poor attention to detail during the installation process.  

Why Is My Drain Line Leaking?


Just as with the hoses that connect your brine tank to your main water softener tank, your drain line can be made out of several different types of material. 

Lack of constant drain line use can cause these drain pipes or drain hoses to become brittle and crack and eventually start to leak.

A drain line can also leak where they connect into the bottom of the brine tank. Water softener drain piping is also very fragile so you have to be careful not to step on it when moving around your softener. 

How Should I Fix A Leaking Water Softener?

Here are your two choices when it comes to resolving water softener leaks:


Softeners are not very complex pieces of water treatment equipment. That means that you can fix many of the above-mentioned leak problems yourself.

This is especially true when it comes to replacing O-rings and seals that don’t require much technical knowledge to carry out. Leaky connections can also be easily tightened or replumbed so they are once again watertight.

Replacing broken or cracked pipes and lines are also something that can be mastered very quickly.

Cleaning your own brine tank to keep it performing well is also something that’s a DIY water softener overflowing solution. Just remember to be gentle around the edges of the tank while doing it.        

Call a Professional

There are some water softener leaks that you probably won’t want to try and fix yourself. This includes dealing with cracked brine and resin tanks. These are the types of repairs that are best left to a plumber or other water treatment professional.

You will also want an opinion from an expert as to whether a cracked water softener tank should be repaired or replaced. I also recommend calling a water softener pro to handle any repeated leaking problems that you have.

Should You Get A New Water Softener?

It also may be the case where you need to strongly consider buying a brand-new water softener. Something that becomes more likely if your water softener is over 10-years old. This is also recommended if your water softening system is now requiring frequent repairs or is becoming ever more difficult to maintain.     

Purchasing a quality water softener will also benefit you by saving water, using less salt, and smartly performing important automatic functions such as system regeneration.   

Don’t Let Water Softener Leaks Go Unrepaired for Long

Keep in mind there is no such thing as a small leak on a water softener that is OK to ignore. Small leaks inevitably become bigger leaks and may also be a sign of bigger softening system concerns.

As a general rule, if you have even minor mechanical and plumbing aptitude, you should be able to handle most leaky water softener repairs yourself.

If you are intimidated and unsure when debating as to whether or not attempt to do any type of DIY water softener leak repair yourself, don’t stress out over it and let a water treatment pro take care of that leak issue for you.  

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Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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