Do All Water Softeners Need a Drain

Do All Water Softeners Need a Drain? FAQs Answered

One of the most important maintenance procedures for a water softener is draining it regularly. The drain line should be set up correctly so that the water softener drains effectively. It should also be set up in such a way as to prevent backflow.

This article will answer the most common water softener draining questions, including the various drain line options, where to drain, the frequency of draining, and how to set up a drain line.

water softener

Why Do Water Softeners Need to Be Drained?

During the regeneration process, brine flows into the resin tank and re-ionizes the resin beads with sodium. During the ion exchange, the calcium, manganese, and other minerals deposit in the water that is inside the resin tank.

To keep the water softener working efficiently, you need to get rid of the deposited crud at the bottom of the resin tank. This is where draining the tank through a drain line comes into play.

If you do not drain frequently and effectively, there will be an excessive buildup of the minerals on the resin tank. This inhibits ion exchange from the incoming water, which results in hard water flowing out of your tap.

Over time, the buildup can damage the softener resins, which are quite expensive to repair. In some cases, you may need to replace the entire resin tank.

What Are the Various Drain Line Options?

Draw line options vary depending on material and size. There are two main options for drain line materials: Soft plastic or PVC. The most common size is ½” although there is an option for ¼.” Whichever size you choose, the drain line should fit well into the water softener.

Check the manufacturer’s manual for recommendations on the draw line size and material of your water softener.

Most “Big Box” water softeners come with a soft plastic drain line. This type of drain line is soft, squishy, and can be pinched together with your fingers. Typically, it is either dark green or clear in color.

Although they do their job well, for the most part, they are likely to collapse within a few years of use or even block.

On the other hand, the CPVC or PVC drain lines can be bought from a plumbing or water specialist store. They are harder and can last up to 25 years. They are less likely to break as a result of blockage or freezing.

Where Should You Drain a Water Softener Discharge?

You should not connect the water softener drain line directly to a waste line from a household plumbing system in most states. However, you can drain into a laundry sink or a floor drain.

While floor drain is a popular option, you should check your local area codes to determine if there are drainage regulations that apply.

The laundry tray method works really well but will violate most local area codes if it does not have an air gap. The solution is to connect the drain line to a pre-built air gap fitting.

Also, do not put a stopper or laundry on the sink as the discharge water may flood and overflow.

Some people who use the laundry sink method report that the air gap causes the discharge water to flow out with high pressure splashing around or out of the sink.

While this issue can be resolved by extending the drainpipe closer to the tray, dirty water could siphon into the supply line.

Water softener plumping experts recommend reducing the water softener pressure setting to lower discharge pressure. It would also help to direct the discharge water on the tray’s wall at an angle instead of the bottom.

Or use a drain pipe that is wider towards the end as it will reduce the velocity of the water and consequently its pressure.

culligan water softener in house

Can You Drain a Water Softener into a Sump Pump?

Although draining into a sump pump, particularly through a floor drain, is viable, it may not be an ideal option. Sump pumps are not designed to handle mineral deposits and draining your water softener discharge inside may accelerate its rate of deterioration.

Besides, most companies will void their sump pump warranty if they find out that you drain water softener discharge into it.

Can You Drain a Water Softener Outside?

It depends on your local area’s regulations and environmental laws. In some areas, it is allowed but prohibited in others. In areas where it is allowed, avoid draining into a flower bed, garden, or lawn as the high mineral levels in the discharge water make the soil unable to support plant life.

Alternatively, you can dig a dry well in your yard where the discharge collects and drains below the ground. Although you do not need any approval to install a dry well, ensure that it is under the freeze line and it has adequate storage capacity for the expected water output.

Also, it is recommended that you do a soil test before installing the dry well. If you set up in an area where there is clay soil, it will inhibit water flow to the underground, resulting in flooding. In such a case, you might need to dig deep to install the dry well.

Can You Drain a Water Softener Into a Septic Tank?

Most states prohibit draining a water softener discharge into a septic tank as it may cause it may damage it. If the laws in your area are not prohibitory, you can drain into the septic tank either through a floor drain or laundry drain.

However, keep in mind that draining excess water into a septic tank can cause an overflow or a backflow; therefore, ensure you have a backup drain field.

How to Install a Water Softener Drain Line

In most cases, water softeners have two drain tubes. One tube is usually connected to the brine tank to serve as an overflow drain. The other connects to the control valve and disposes of the backwash water from the resin tank after the regeneration cycle.

The two tubes are then directed to the main drain tube. Note that the two drain tubes should not be connected. The main drain tube can either be run into a floor drain or a standpipe that drains into a utility tray, sump pit, or sewer line.

Do You Need to Connect an Air Gap to the Drain Line?

In most areas, you are required to use an air gap to connect a water softener drain line to the home drain system. This prevents a back-siphoning of the drain water back to the water softener.

For septic tank outlets, the air gap prevents the sewer smells from coming back into the drainage system or water softener.

Some air gap fittings allow you to connect your water softener’s drain line directly to a standpipe or drainpipe. Alternatively, a drainpipe with a trap can serve as an air gap.

This can be achieved by leaving a small space between the drain pipes and the drain tube.

How Often Should You Drain a Water Softener?

The frequency of draining depends on factors such as:

  • The volume of water the water softener processes over a given time
  • How hard the water is
  • The water softener capacity
  • Age of the water softener

The higher the volume of water that passes through the water softener, the harder the water, and the smaller the resin tank, the more frequently you will need to drain. Over time, the water softener loses its efficacy and may need to regenerate and drain more frequently – in some cases, several times a day.

Otherwise, most water softeners regenerate and drain every 3-5 days. Others are either set drain after a certain length of time or water volume.

Blocked Drain Line

What Should I do if the Drain Line is blocked?

The mineral deposits from the regenerated resin beads may accumulate in the drain line reducing its diameter. Freezing can also cause the drain line to get blocked.

A narrower drain line restricts wastewater flows out of the resin tank, resulting in excess water in the resin tank. It can also lead to an accumulation of the minerals on the resin beads, causing an outflow of hard or minimally softened water.

Regularly cleaning the drain line will reduce the incidence of blockage. It is frozen, pass some warm water through to thaw the ice or wrap a piece of cloth that has been dipped in warm water around the frozen.

Do not apply direct heat as it melts the draw line. If these methods do not resolve the blockage, you will have to replace them with new draw lines.

Why Is My Water Softener Always Draining?

The water softener should not drain non-stop. The primary reason that a water softener keeps draining even after the regeneration process is over is a fault in the main piston. It could have failed to reset, or there is a leakage in the seal.

If a power outage occurs in the middle of a regeneration cycle, when it comes back, the water softener computer system may not reset accordingly.

As a result, the regeneration process may proceed indefinitely, causing water in the resin tank to drain continuously. To resolve, restart the water softener’s computer and reset the regeneration cycle.

An electrical issue could also cause the water softener to keep draining. If power is not getting to the water softener computer, then the regeneration process won’t be regulated properly.

Check if the computer display is blank. If blank, confirm whether the water softener power plug is connected to the socket and switched on. If that is not the issue, either the electrical system of the water softener is faulty, or your house’s electrical system is faulty.

To test the house electrical system, plug in another electronic device. e.g., a phone, radio, or torch. If power is transmitting to the device, it means that the house electrical system is working, and that of the water softener may be faulty.

Consult with a water softener specialist to help resolve the issue. Also, confirm whether the power cord connecting to the water softener is working properly.

A computer malfunction can also cause non-stop draining. A computer malfunction can occur due to a power surge or spike.

This causes the computer to lose power resulting in memory loss or faulty regenerating settings. To resolve, restart the computer and reset the regeneration settings.

If these measures fail, put the water softener temporarily in bypass mode and reach out to your water softener technician.

Why Is My Water Softener Not Draining?

The are several reasons that could cause your water softener to drain. The most common reason is either the drain line being blocked or kicked.

The minerals may have deposited in the drain line, significantly reducing its diameter, causing the water not to drain out.

Also, if a big chunk of salt happens to flow from the brine tank into the resin tank, it can clog the drain line when flowing out. A salt crystal blockage can be resolved by pouring hot water through the drain line or through suction.

If the water softener is installed too high relative to where it is draining, it may prevent the water softener discharge from draining out through the drain line.

This often happens when the drain line and pipe are not lower than the bottom of the resin tank. This is an installation issue and should be corrected accordingly.

If the regeneration process stopped mid-way for reasons such as computer power loss or power outage, the water softener might not drain.

Finally, there could be an issue with suction whereby the venture seals may have dried up, therefore not providing suction.


Although water softener draining is an automated process, it needs to be set up so that it operates effectively and efficiently. Ensure you use the right type of drain lines. Adhere to your local area regulations on where to drain to.

If the water softener is consciously draining or not draining at all, troubleshoot the common reasons discussed above and resolve accordingly. Otherwise, contact your water softener specialist or plumber.

Here is a video the provides further information about water softener draining.

Amanda Perkins

Amanda began her career as a technical writer for a healthcare group in 2008. Years after getting married and starting a family, she joined her husband Joshua on the Water Filter Authority journey to educate other families and households about safe, affordable, and effective water filtration systems.