Do All Water Softeners Need a Drain?

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The water softener installation process usually involves attaching a drain line. But why do water softeners need a drain, and is a drain required for all softeners?

We’ve shared what you need to know in this guide.

πŸ“Œ Key Takeaways:

  • Salt-based water softeners discharge waste water during the regeneration process, and a drain pipe is required to send this water down a drain in your home.
  • A traditional water softener has to be connected to a drain. There’s no option to simply not install the drain pipe.
  • You can empty a softener drain line into a laundry tray, a floor drain, a washing machine, a sump pit, or a utility sink.

πŸ€” Do All Water Softeners Need A Drain?

πŸ’‘ Yes, all salt-based water softeners need a drain.* Why? Because these water softening systems discharge waste water during regeneration – and without a drain, there would be nowhere for this water to go.

The main drain line is usually attached to the control valve on the resin tank. Contaminated drain water flows down this pipe and into a floor drain, a sump pit, or a similar drain in your home.

Most water softeners have a second drain line attached to the brine tank, called the overflow drain line. This tube sends excess water out of the brine tank in the event of a blockage or overflow.

The exception here is salt-free water softeners, otherwise called water conditioners. These don’t need a drain because they don’t have resin and don’t use ion exchange. They also don’t physically remove hardness minerals from water, so they don’t need to regenerate to flush these minerals out of the tank.

Connecting a water softener drain line

πŸ“₯ Why Do Water Softeners Need A Drain?

Water softeners need a drain because they discharge water during the regeneration process.

To understand why a water softener system needs a drain line, we need to know how the regeneration process works.

Simply put:

  1. A water softener resin tank contains a resin bed, which is loaded with sodium ions.
  2. As hard water flows through the system, the sodium ions leave the resin beads and are replaced by calcium and magnesium minerals.
  3. Eventually, the resin becomes depleted of sodium ions and saturated with calcium and magnesium. To flush these minerals out of the resin bed and replenish the sodium ions, backwash water is sent through the resin tank.
  4. Water containing the collected hardness minerals is washed down the water softener’s drain tubes.

About 25 to 65 gallons of water are wasted per regeneration cycle.

πŸ”Ž Where Can You Drain A Water Softener?

There are a few locations you can drain a water softener system:

  • A laundry tray
  • A floor drain
  • A washing machine
  • A sump pit
  • A utility sink
  • Any other properly trapped outlet*

While you can use a laundry tub or any other sink for your water softener’s drain hose, it’s best to discharge the wastewater to the sewer system when you can (as long as this isn’t breaking any local plumbing codes).

However, laundry trays are a convenient option since they function as an air gap, so you won’t need to worry about making your own.

We advise you to consider nearby drain options when you’re deciding where to install the water softener.

The system should be installed as close as possible to your main water pipe’s point of entry into your home, but also in a location that’s easy to connect to your plumbing system, such as a utility room, a basement, a garage, a crawl space, or somewhere near your hot water heater.

πŸ“Œ A properly trapped outlet is used if you’re connecting your softener drain directly to an outlet rather than a drain. It stops anything from coming backward through your plumbing, including bad sewer smells. You could connect the outlet to your sewer or (if allowed in your area) dig a dry well with a properly trapped outlet.

Water softener drain line outlet

πŸͺ› How To Connect A Water Softener Drain Line

Installing the drain line in a water softener system is one of the last things you’ll do, once the tanks have been plumbed into your water supply and you’ve installed the tubing connecting the two.

Remember, there are two drain tubes in a water softener: a tube for the wastewater during regeneration and a dedicated drain pipe for brine overflow. These tubes are purposefully designed to be separate, so don’t try to connect them together during the installation.

To connect the drain tubes in your water softener, follow these steps:

  1. Use hose clamps to attach flexible tubing (0.5-inch in diameter) to the drain elbows on the brine tank and the control valve.
  2. Run the tubes to the drain location.
  3. Anchor the drain tubes to a floor drain/laundry tray/any other properly trapped outlets, making sure the drain line is at least 1.5 inches above the drain receptor, or attach the ends of the drain tubes to an air gap fitting (if you’re using one).

Make sure to check the instructions in your user manual and refresh yourself on your local laws before you install a drain for your water softening system.

πŸ“₯ Can A Water Softener Be Directly Connected To A Sewer Line?

No, water softener drain lines should NEVER be directly connected to a sewer line. You should always leave an air gap when connecting your water softener to a drain.

An air gap is as it sounds – the gap between the end of the drain line and the drain receptacle (e.g. a utility sink, floor drain, laundry tray, etc.). The air gap should be at least twice the diameter of the drain line, and should always be at least 1.5 inches above the top of the drain receptor.

Why leave an air gap rather than connecting the water softener drain directly to the drain receptor?

Because with a direct connection, there’s always a chance that water could flow back through the drain and into the water softener.

Let’s say you connected your water softener’s drain lines directly to a sewer pipe. If a suction was created in the sewer systems (due to firefighting pumping equipment connected to the line in the area, for example), it could be strong enough to send fluid from the pipes into your softening system, causing sewage to contaminate the tanks and your water supply.

If you play it safe and keep your drain hose separated from your sewage or septic system with an air gap, you won’t have this concern.

In most states, it’s illegal to connect a water softener’s drain directly to sewage or septic systems without some form of air gap or air gap fitting. An air gap fitting makes it possible to connect the water softener’s drain tubes directly to a drainpipe or standpipe while preventing contaminated drain water from back-siphoning into the unit.

Installing sewer pipe

πŸ“‘ Final Word

If you have a traditional salt-based softener, you need some form of drain connection.

Installing softener drains isn’t too difficult – but make sure you know your local laws before you do something that might be prohibited.

Some areas allow for outside discharging, some don’t. Some states let you discharge straight into a sewer system, while others are stricter.

If in doubt, speak to a local plumber. They’ll be well-versed in your local plumbing codes and can tell you what is and isn’t allowed when it comes to installing water softener drain pipes.

❔ Do All Water Softeners Need a Drain? FAQ

Where should a water softener drain hose be?

A water softener’s drain line can be run to various different drainage options. Most softener drain lines are run to floor drains, but it might be better for you to connect the drain line to a sump pit, a laundry sink, or a standpipe for washing machine drainage.

Can you install a water softener without a floor drain?

Yes, you can install a water softener without a floor drain. You have a few other drainage options, such as sump pumps, a laundry tray or a washing machine drain, a utility sink, or any other properly trapped special outlet. Just make sure you have a drain no more than 30 feet away from the water softener and with an elevation above the floor of less than 8 feet.

Can I drain a water softener into my sump pump?

Yes, you can drain a water softener into a sump pump, and this is a popular choice in states that don’t allow discharge water to be directed into the sewer. However, a sump pump drain line setup has its setbacks. Many sump pump manufacturers advise against draining a water softener into a sump because its components aren’t designed for saltwater exposure. The water’s corrosive properties could damage the sump, and using a sump pump for water softener drainage often voids its warranty.

What happens if a water softener drain line gets blocked?

If your drain line gets blocked or the drain line size decreases (due to getting kinked, for example), water won’t be able to leave the softener at a fast enough rate during a regeneration cycle. This could prevent the softener from draining properly, resulting in excess hardness minerals and iron in the resin bed. A completely blocked drain hose could even cause the softener to flood.

Can you drain a water softener outside?

In some states, you can drain a water softener outside, while in others, you can’t. Usually, if you are allowed to drain a water softener outside, you won’t be able to grow plants in the drain location unless you did a dedicated dry well for the drain water. Check your local authority’s website or contact a local plumber for more information.

  • Laura Shallcross
    Senior Editor

    Laura is a passionate residential water treatment journalist who holds an undergraduate degree in Print Journalism and a master’s degree in Creative Writing. Over a span of 5 years she's written on a range of topics including water softening, well water treatment, and purification processes.

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