How to Install a Whole-House Water Softener

First, select the best location for your water softener. It should be on a level surface in a dry, protected area like a basement or garage. The location must be close to the main water supply line, near a standard 110-volt electrical outlet, and have access to a floor drain or utility sink for the regeneration discharge. Ensure there is enough space around the unit for future maintenance and adding salt. The softener should be installed after the water meter but before the water heater, tapping into the main cold water line that supplies the house.

Begin by shutting off the water to the entire house by closing the main water shutoff valve. If you have an electric water heater, turn off its power at the circuit breaker panel. If you have a gas water heater, turn the control knob to the 'PILOT' position. Next, open faucets on the highest and lowest levels of your home to completely drain the water from the pipes. This will relieve pressure and prevent a watery mess when you cut the pipe.

Identify the main cold water line you will be tapping into. Place a bucket underneath your work area to catch any residual water. Using a tubing cutter, make a clean, square cut to remove a section of the pipe where the softener's bypass valve will be installed. The length of the section to remove depends on the dimensions of your bypass valve and the fittings you'll use (typically two 90-degree elbows). After cutting, use a deburring tool to clean the inside and outside edges of the cut pipe ends to ensure a proper fit for the new fittings.

This step involves creating the plumbing assembly that diverts water to and from the softener. First, clean the outside ends of the cut main line and the inside of two 90-degree copper elbows using sandpaper or a wire brush. Apply a thin layer of flux to all cleaned surfaces. Fit the elbows onto the pipe ends, pointing them towards the location of the softener. Using a soldering torch, heat the joints evenly. Once hot enough, touch the lead-free solder to the seam; it will melt and be drawn into the joint. Allow the joints to cool completely. Next, attach the bypass valve assembly that came with your softener to the two new pipes leading from the elbows, following the manufacturer's instructions. This may involve soldering on threaded adapters and then using pipe wrenches to tighten the valve connections.

With the bypass valve in place, measure and cut two lengths of copper pipe to connect the valve's inlet and outlet ports to the corresponding ports on the water softener control head. Ensure you follow the arrows on the valve indicating the direction of water flow ('IN' and 'OUT'). The pipe from the main supply goes to the 'IN' port, and the 'OUT' port pipe returns to the main line to feed the house. Assemble these connections using the same soldering technique as before or by using the manufacturer-provided connectors (which may be plastic quick-connects or threaded fittings).

Your water softener has two hoses that need to be routed to a drain. The first is the main drain line from the control valve, which expels brine and backwash water during regeneration. The second, smaller hose is the brine tank overflow line. Cut the provided flexible drain tubing to length and attach it to the control valve's drain fitting, securing it with a clamp if provided. Route this tubing to the floor drain or standpipe, ensuring there is an air gap of at least 1.5 inches between the end of the tube and the drain to prevent back-siphoning. Do the same for the brine tank overflow hose, routing it to the same drain.

This is the moment of truth. First, ensure the bypass valve is in the 'bypass' position, which allows water to flow through your new plumbing but not into the softener. Go to the main water shutoff and open it very slowly to allow the pipes to fill gradually, which helps prevent water hammer. Carefully inspect all the new joints you soldered or tightened for any signs of leaks. If everything is dry, slowly open the bypass valve to the 'service' position. You will hear water flowing into the softener tank. Again, check all connections, including those at the softener unit itself, for leaks.

With the plumbing complete and leak-free, you can now set up the softener. Plug the control head's power adapter into the nearby electrical outlet. Add water to the brine tank until it's about one inch above the salt grid plate. Then, pour water softener salt pellets into the brine tank until it's about half full. Program the control head according to the manufacturer's manual. You will need to input your water hardness (in Grains Per Gallon, or GPG), the current time, and your preferred regeneration time (typically an off-peak time like 2 AM).

The final step is to run a full manual regeneration cycle. This will ensure the resin bed is fully saturated and ready to soften water, and it purges any remaining air from the system. Find the 'Regen' or 'Regenerate' button on the control head and press and hold it as instructed by the manual to initiate the cycle. The softener will go through several stages (backwash, brine draw, rinse, etc.) which can take up to two hours. Once the cycle is complete, your system is fully operational. Remember to turn the power back on to your water heater.