Sometimes you might need to disconnect your water softener. It may break and need to be sent out for repair; you may want to swap it out with a new one if it's old and not performing well; you may want to drain it and decommission it to avoid freeze damage in the case of a vacation home. Water softener manufacturers thought of this, and all water softeners have a bypass valve. The bypass valve lets you isolate the water softener and bypass it—the water from the municipal supply flows straight into the household system, without going through the water softener.
Unplug the power supply to the water softener.
Close the main water supply to the house. You can usually find it adjacent to the meter.
Open a tap in the house to vent pressure to the softener. Make sure it's a tap that's in the soft water system. Use a tap or faucet that you know is soft—like the kitchen sink.
Take a look at the copper pipes near the water softener. You should see the bypass valve behind the water softener. There are two kinds of bypass valves, a three valve bypass and a single bypass. You can identify a three valve bypass because it has three valves—an outlet valve, an inlet valve, and a bypass valve. The single bypass valve is the last piece of plumbing in the copper before the softener. There's a stopper-like plug which will be sticking out a bit which is the setting for service.
Push the single bypass stopper-like plug in to bypass the water softener. In the case of the three valve bypass, close the inlet and outlet valves and open the bypass valve. The water softener is now isolated.
Remove the large holding clips at the softener inlet and outlet. Separate the water softener pipes from the copper pipes. The water softener is now disconnected. Turn the household water back on.