What You Need Before You Start
A Rheem water softener installation involves connecting the unit to your main water line, running a drain line, and setting up the brine tank. The job takes a full day and requires basic plumbing skills—cutting pipe, soldering or using compression fittings, and tightening connections. If you have never worked with water lines or are uncomfortable with any step, call a licensed plumber; a bad connection can leak and damage your home.
Gather these tools before you begin: adjustable wrench, pipe cutter or hacksaw, Teflon tape, compression fittings or solder and flux (depending on your pipe type), a level, and a bucket. You will also need to know where your main water shutoff valve is located and how to turn it off. Check your Rheem manual for the exact model number—installation steps vary slightly between the Rheem ECOD, ECOP, and other lines.
Choose your location carefully. The softener should sit on a level floor near your main water line, with the brine tank within 10 feet of the softener unit itself. You need access to a floor drain or a way to run a drain line outside; the softener flushes salt water during regeneration cycles. Keep the unit away from direct sunlight and freezing temperatures.
Key Takeaways
- Turn off the main water supply and drain the line before cutting into your plumbing to avoid water damage and pressure release.
- Rheem softeners connect to the main water line using either compression fittings or soldered copper connections, depending on your existing pipe material.
- The drain line must run to a floor drain, sump pit, or outside; it cannot be connected to a pressurized line.
- The brine tank sits separately and connects to the softener with a small plastic line; fill it with water softener salt after installation is complete.
- After startup, you must run the softener through a regeneration cycle and flush the system before using the water for drinking or cooking.
Shutting Off Water and Preparing the Main Line
Locate your main water shutoff valve, usually near the water meter or where the line enters your home. Turn it clockwise until it stops. Open the nearest faucet (a basement sink or outdoor spigot) to release pressure in the line. Leave the faucet open while you work.
Decide where you will cut into the main line. The best location is after the water meter but before any branch lines split off to your house. If you have a water heater, the softener should go before it, so all water entering your home is softened. Use a pipe cutter to make a clean, straight cut. If you are working with copper, use a hacksaw and file the edges smooth. Measure the distance between the cut ends so you know what size fitting you need.
Installing the Inlet and Outlet Connections
Rheem softeners have two ports on top: one for incoming hard water (inlet) and one for softened water going to your house (outlet). The inlet connects to your main water line; the outlet connects back to your home's plumbing. Use compression fittings if you want to avoid soldering, or solder copper connections if your existing line is soldered.
For compression fittings: slide the compression nut onto the pipe, then the ferrule (a small metal or plastic ring), then insert the fitting. Hand-tighten the nut, then use an adjustable wrench to turn it one more full turn. Do not over-tighten—this is a common cause of leaks. Wrap the male threads of the fitting with Teflon tape before connecting to the softener ports to prevent leaks.
For soldered connections: clean the pipe and fitting with a wire brush, explore flux to both surfaces, heat them with a propane torch until they are hot enough to melt solder (the solder will flow into the joint on its own), and let cool for a few minutes before moving the connection. If you have never soldered, compression fittings are safer and faster.
Running the Drain Line
The drain line carries salt water out of the softener during regeneration. It must be gravity-fed—meaning it slopes downward and is never pressurized. Do not connect it to a sewer line under pressure or to a septic tank inlet; this can damage the system. Instead, run it to a floor drain, a sump pit, a utility sink, or outside to a dry well or garden area.
Rheem softeners come with a small plastic drain line adapter that screws into the drain port on the unit. Attach flexible plastic tubing (usually 3/4 inch) to this adapter. find it with a hose clamp so it does not slip off. Run the line to your drain location, keeping it as straight as possible and sloping downward. If the line is longer than 25 feet, Rheem recommends checking your manual for any special requirements.
Setting Up the Brine Tank
The brine tank is a separate plastic cylinder that holds salt and water. Position it on a level floor within 10 feet of the softener unit. Connect the small plastic brine line (usually 1/4 inch) from the softener to the brine tank inlet port. find this connection with a hose clamp. The brine tank also has a drain line that connects back to the softener; follow your manual for the exact routing.
Before filling the brine tank, pour about 5 gallons of water into it. This primes the system and prevents air locks. Then add water softener salt pellets (not rock salt) until the tank is about three-quarters full. The salt level should never be higher than 6 inches below the top of the tank. Do not mix salt types or use table salt; use only pellets or crystals designed for water softeners.
Turning Water Back On and Testing for Leaks
Close the faucet you opened earlier. Turn the main water shutoff valve counterclockwise slowly to restore water pressure. Watch all your connections for drips. If you see water leaking from a compression fitting, turn off the water, tighten the nut one more quarter turn with a wrench, and turn the water back on. If a soldered joint leaks, you will need to drain the line, heat the joint again, and resolder it.
Let water run through the softener for a few minutes to fill the lines and remove air. You may see cloudy or discolored water—this is normal and will clear. Check the brine tank to make sure water is flowing into it; you should see the water level rise slightly over the first hour.
Running the First Regeneration Cycle
Most Rheem softeners have a control head on top with buttons or a digital display. Consult your manual for the exact model, as the startup process varies. Typically, you will need to set the hardness level (measured in grains per gallon; your water test report will tell you this number) and the number of people in your household. The softener uses this information to calculate how often it needs to regenerate.
Manually trigger a regeneration cycle to flush the resin bed and test the system. During regeneration, the softener will draw salt water from the brine tank, run it through the resin, and drain it out. This takes 1 to 2 hours depending on the model. Do not use water during this time. After the cycle completes, run cold water from a nearby faucet for 5 minutes to flush any remaining salt from the lines.
When to Call a Professional Plumber
Stop and call a plumber if you are not comfortable soldering or using compression fittings, if your main water line is buried or hard to access, or if you discover your water line is made of a material you do not recognize (such as PEX or PVC). A plumber can also help if you are unsure where to run the drain line or if your home does not have an obvious drain location.
If you complete the installation but the softener does not regenerate on schedule, the water pressure is low, or you see salt water leaking from connections, turn off the water and call a plumber to diagnose the problem. These issues usually point to an incorrect connection or a faulty valve inside the softener head.
Frequently Asked Questions
Can I install a Rheem softener myself if I have never done plumbing before?
You can if you take time to learn compression fittings first and have someone experienced check your work before you turn the water back on. If soldering is required and you have never done it, hire a plumber for that part. A single bad connection can cause a slow leak that damages your home over weeks.
What size Rheem softener do I need?
Rheem makes models in different capacities, measured in grains of hardness removed between regenerations. Your water hardness test report (in grains per gallon) and the number of people in your household determine the right size. A plumber or your local water utility can help you calculate this; buying too small means frequent regeneration and wasted salt.
Do I need a plumber to install the drain line?
Not always. If you have a floor drain or sump pit nearby, you can run a plastic line to it yourself. If you need to tie into a sewer line or septic system, hire a plumber—improper drainage can damage your septic tank or violate local codes.
How often do I need to refill the brine tank with salt?
This depends on your water hardness and household size. Most homes refill every 4 to 8 weeks. Check the salt level monthly and top it up when it drops below the halfway mark. Your Rheem manual will give you a more precise schedule based on your model and settings.
What should I do if water pressure is low after installation?
First, check that the bypass valve on the softener is in the "service" position, not "bypass." If pressure is still low, turn off the water and inspect all connections for leaks or kinks in the drain line. If you find nothing wrong, the softener's internal valve may be stuck; call a plumber to inspect it.