There are three possible conditions a water softener can be in: "service," which is when the water softener is providing you with soft water; "regeneration," sometimes called recharging, when the softener is cleaning itself and preparing for the next service period; and "bypass," when untreated hard water bypasses the water softener and goes directly into the house. You should only turn a water softener off after first putting it in the "bypass" mode.
Shut off the main water supply to the house. The shutoff lever is often adjacent to the meter.
Release pressure on the water softener and the household water supply by opening a faucet. Use one you know is being serviced by the water softener.
Find the bypass valve. It will always be in the intake and outlet copper pipes at the back of the water softener. There are two types: A single-bypass valve looks like a barrel with a stopper; and a three-valve bypass is easy to spot because it has three valves.
Press the stopper in on the single-bypass valve to bypass the water softener plumbing. Close the inlet and outlet valves and open the central bypass valve in the case of the three-valve system. Use the plumber's wrench for leverage if there aren't easy to grip handles on the three-valve system.
Turn the water back on to the house.
Unplug the water softener. It is now off. All water from the street will bypass the water softener too.