Step-by-Step Guide on How to Install a Water Softener in a Pre-plumbed House

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Hard water causes multiple problems for your skin and most household functions. But you can prevent these issues by installing a water softener. The installation can be simple or difficult, depending on the location site, type of softener, and the plumbing state of your home.

For a pre-plumbed house, you don’t have to be a professional to install the system. You only need the right materials and knowledge. Here’s how to install a water softener in a pre-plumbed house.

What You Need
  • Pipe cutters
  • Tape measure
  • Copper fittings
  • Flexible tubing
  • Pipe wrench
  • PVC solvent/flux
  • Union fittings
  • Torch and solder
  • Gate valves
  • Teflon tape
  • Tubing/copper pipe
  • Compression fittings
How to Install a Water Softener in a Pre-plumbed House

1. Turn Off the Water Supply

To avoid causing a major leak inside the house, turn off the mainline’s water supply.

2. Drain Out the Pipes

Ensure all pipes are drained out. Open the tap at the lowest level and let the water run out.

3. Turn Off Electric Water Heater

If you have an electric water heater, ensure to turn it off and all the power to the water heater, as well.

4. Locate Where to Install the Softener

If you intend to install a whole-house system, you should place the softener near the main water entry point. This should be before the water line leading to your water heater.

5. Put the Softener in Place

Place your water softener in position and ensure it stands level.

6. Cut the Main Water Supply Line

Cut into the mainline using a pipe cutter. This allows for the installation of elbow fittings. You can put a bucket under the cutting point to collect any water remaining in the pipe.

To cut the pipe, tighten the pipe cutter onto it and rotate it around the pipe until it cuts through. Thereafter, sand down the edges.

7. Install an Elbow Fitting

An elbow fitting will enable you to feed the softener. A bypass valve allows you to feed water around your softener. The elbow fitting will enable you to run two lines to both the inlet and outlet ports of the valve.

In case you want the hard water to flow outside, put a T-fitting at some point before the mainline reaches your softener’s inlet.

8. Install the Pipes

You need to cut the pipes leading to the bypass valve and solder the fittings and nipples to the pipes. Next, install the pipes to the bypass valve(s).

If the pipes are of different sizes, you can use a small-size fitting to get the right size. You can also use compression fittings to enhance the attachment of the pipes to your softener.

9. Connect the Drainpipe

Connect the drainpipe to the water softener. You’ll need clamps to hold it in place and conveniently direct the pipe to the utility sink or the drain. The drainpipe should be at least 2 inches from the drain hole to prevent brine water from siphoning back to your softener.

10. Connect the Overflow

You’ll need to attach an overflow tube to the overflow valve to prevent any overflow in the brine tank. You’ll also have to clamp and direct the tube to the drain. Ensure that it’s above the drain hole and it doesn’t whip.

11. Install the Brine Line

The brine line will enable the brine to flow into the resin tank during the regeneration process. With this step, your softener should be ready for use. But first, ensure that all the pipes lead to the right places and all connections are secure.

12. Place the Softener in Bypass

Now, turn on the water and let it run through the water softener. This helps ensure there are no sediments in the pipes and allows you to locate any water leaks.

13. Change the Valve to Backwash Position

Press the regenerate button and hold it down to allow the unit to cycle. Wait for it to reach the backwash position, then plug in the softener.

14. Partially Open the Bypass Valve

Allow the water to flow into the resin tank and out the drain. Open the main water supply until the water starts flowing with no spurts and abnormal noise. Next, fill both tanks with water and salt – follow the manufacturer’s instructions.

15. Plug in the Softener

Using the regeneration button, allow the unit to finish a full cycle again until the service setting is on.

16. Configure the System

Use the manufacturer’s instructions to program your softener as per the hardness level, regeneration period, and system type. Some softeners regenerate on demand, hence saving you the need to frequently refill the salt.

Note that even the best water softeners will only soften hard water. They may save your plumbing system, water appliances, and improve your shower experience, but they won’t remove contaminants other than hard minerals.

A water softener will not remove sediments, chlorine, chloramine, heavy metals, or other contaminants that may affect your health or leave a bad taste and smell in your home water. You may have to learn how to install a whole house water filter to remove those contaminants.


That’s your straightforward step-by-step guide on how to install a water softener in a pre-plumbed house. The installation process should take you between 1-4 hours.