How to Install a Water Softener

In this video, This Old House plumbing and heating expert Richard Trethewey and water-quality specialist Doug Oberhamer show how to soften mineral-rich hard water. Learn more about how much a water softener system costs.

Worth the Investment: Hard water may not be a health hazard, but it takes a toll on your home. As water quality expert Patrick Smith explained on a This Old House project, hard water “can also wreak havoc on water heaters” as minerals settle to the bottom over time—meaning the cost of a professional water softener installation can pay for itself by extending the life of your appliances and plumbing fixtures.

Steps for Installing a Water Softener

1. Dig a trench from the water main to the garage.
2. Use a drill to bore two 1-inch-diameter holes through the garage wall.
3. Clean and de-burr the ends of the copper water-supply pipes.
4. Buff clean the pipe ends with emery cloth.
5. Solder together the copper water-supply pipe and fittings. Run two pipes from the water main to water softener inside the garage.
6. Make the pipe connections at the water main and at the water softener.
7. Attach a discharge pipe to the water softener and end it at a nearby utility sink or floor drain that’s connected to a sewer line.
8. Fill the storage tank with water-softener salt, and then check the salt level at least once a month.

Pro Tip: When choosing a water softener, look for a unit with a built-in water meter rather than a simple timer. Timer-based units regenerate on a set schedule whether they need to or not, but a metered unit only regenerates when necessary — saving salt and water.

When cleaning pipe ends, use a tool with a serrated convex cylinder inside to clean the interior of the pipe, then flip to the concave side to clean the outside. Follow up with emery cloth to ensure a bright, oxide-free surface for a solid solder joint.

Pro Tip: If your home has an exterior stucco wall, wrap the copper pipes with black pipe wrap tape before running them through. The wire mesh used to attach stucco to the house can react with copper, so the tape protects against corrosion.