Why is My Water Softener Overflowing?

We love water, but we certainly don’t love it where it doesn’t belong—like pooled on the floor of our utility rooms. Typically, there are several gallons of water inside a softening system’s brine tank, but when your water softener is full of water or your water softener is overflowing, the water is not passing through the tank to the rest of your home the way it’s meant to.

Why is this happening and how can you fix it? An abnormally high water level in a brine tank often suggests a brine line malfunction, stuck float, or a damaged valve. There are a few simple water softener maintenance tips to help determine the cause of an overflow, and how to resolve it. First, a little background on what happens inside a brine tank and how this is important to the water softening process.

Regeneration and the Control Valve

The device in a water softener that controls the flow of water in and out of the mineral and brine tank during regeneration is called the control valve. The control valve determines when it’s time to clean, or regenerate, the resin beads saturated with minerals.

Softening systems need to regenerate periodically to regenerate and keep the resin bed clean. Regeneration removes calcium and magnesium minerals from the resin bed. It begins with a backwash cycle where the valve reverses the flow of water and flushes accumulated from the tank.

A brine solution is pumped into the mineral tank where sodium ions hold fast to hard water minerals on the resin, forcing them off the resin beads. The mineral-rich water is then flushed out of the tank, and down the drain.

After, the tank is filled and rinsed so the process can repeat once again. The resin beads, now coated with salt, attract the calcium and magnesium minerals. When saturated, the control valve begins a new regeneration cycle-- cleaning, then flushing the hard minerals down the drain.

The Overflow Checklist

During normal operation of a water softening system regeneration cycle, water fills the brine tank ¼ to half of the way, then the brine is drawn back into the softener tank to clean the resin. When a softener system isn’t drawing brine to use during regeneration, the water level may stay the same or increase during each backwash cycle.

Brine Tank Full of Water

When your water softener is full of water and has begun to spill out of the brine tank, check for problems that have the simplest solutions before tackling other possible causes. Make sure the brine line is properly attached to the float inside the brine well. The brine line is the tube that connects the tank to the water softener control valve.

Remove the lid from your brine tank and the cap from the brine well inside the tank. Make sure the brine line is fitted securely to the safety float. Water or air leakages will cause a malfunction of your water softening system and an overflow of water in the brine tank.

Other causes of brine tank overflow can be due to obstructions. Look for salt clogging inside the tank. Salt clogs restrict the flow of water entering the brine tank to absorb the salt, and the flow of water drawn out of the brine tank as well.

Clogged Drain Line

Next, check that your drain line isn’t clogged or kinked in a manner that would impede the flow of brine through the brine line. The drain line flow control valve can also develop a blockage. In homes with high iron levels, this is especially common and periodic cleaning is necessary to maintain water movement. If your brine line float control gets clogged with salt, take it out, wash it, and check to make sure it’s working correctly.

Clogging can occur where the brine line connects to the water softener valve. Debris may enter the brine tank and get sucked up through the valve. When this happens, the valve can no longer draw brine. A good cleaning will keep the tubing clear and continue to provide the suction required for the brine draw. If the brine tank overfilled at the last regeneration and has stopped overflowing, this suggests a problem with the brine valve.

Check the Float Cap

Check that your brine level control float cap is still attached securely. These caps can loosen with the normal vibration of a working softener system and on occasion drop inside the brine tank. And if your safety valve fails, water can continually be added to the brine tank causing the water to keep rising.

Brine Tank Injector Obstruction

One of the most common causes of too much water in the brine tank is an injector obstruction. The injector has a very small hole that creates suction or venturi to draw the brine. If that hole becomes clogged it will need to be removed and cleaned. High levels of iron in water, require more frequent cleaning of the injector. If you’re unable to unclog the injector, this is a relatively small and inexpensive part to replace.

If you’ve checked the brine tank and the lines, then it’s possible that the problem lies with the seals and spacers or piston. When a softener is going through the regeneration stage and is not drawing brine, there’s likely a torn seal or plugged injector which will cause the softener to not draw or even refill during the brine draw stage.

To inspect the spacer stack and pistons, remove the drain line and the brine line. While the valve is in service, look to see if water is flowing across the valve. If so, your softening system may require replacement of the seals/spacers or piston. As this is a more difficult job than basic cleaning and maintenance, you may want to enlist the help of a professional installer.

When determining the cause of a brine tank overflow, always use caution when disassembling and cleaning the movable parts of your water softener. Verify that each part is returned to its correct position and securely reattached. Replacing washed and inspected parts in the exact order they were removed will prevent further malfunctioning of your softener.

Water softening equipment may seem complicated but knowing how to troubleshoot some of the most common issues responsible for brine tank overflow, or water softener overflow, can save you time and money. Learning how to remove, inspect, and replace the most important components of your unit will help avoid unnecessary service calls and extend the lifespan of your water softening system.