Locate the circuit breaker that controls the well pump and switch it to the 'off' position. Next, find the main water shut-off valve for your home, typically located where the water line enters the house, and turn it off. This is a crucial safety step to prevent injury and water damage.

The pressure tank is typically a large, often blue or grey, cylindrical tank. The pressure switch is a smaller electrical box mounted directly onto the pipe connected to the pressure tank. It will have a lever or handle for manual operation and often a visible dial or markings indicating pressure settings. Familiarize yourself with the location and appearance of these components.

The pressure switch typically has two sets of numbers indicating the 'cut-in' pressure (when the pump turns on) and the 'cut-out' pressure (when the pump turns off). These are usually marked on the switch itself or visible on a dial. Note these values down. You can also use a pressure gauge if one is installed on the system to confirm the current operating pressure.

The pressure switch has adjustment screws that control springs. Turning the large adjustment screw affects both the cut-in and cut-out pressures. Turning it clockwise increases pressure, and counter-clockwise decreases it. The small adjustment screw fine-tunes the difference between cut-in and cut-out (the differential). Adjust incrementally, no more than 2 PSI at a time, and allow the system to cycle to observe the effect. For example, to raise the cut-out pressure by 2 PSI, turn the large screw clockwise approximately one-quarter turn. Then, turn on a faucet to let the pressure drop and observe the new cut-in pressure.

Once you have made tentative adjustments to the pressure switch, turn the main water supply valve back on. Then, turn the circuit breaker for the well pump back on. Open several faucets in the house (hot and cold) to allow the system to fill and pressurize. Listen for the pump to cycle on and off. Use a pressure gauge attached to a faucet to measure the static pressure (when no water is running) and the operating pressure (when water is running). Adjust as needed, repeating steps 4 and 5 until you achieve satisfactory pressure.

With the power and water shut off (as in Step 1), open a faucet to relieve any pressure. Locate the air valve on the pressure tank (usually covered by a plastic cap). Use an air pressure gauge to check the air pressure in the tank. The air pressure should be 2 PSI below the cut-in pressure of your switch. For example, if your cut-in is 40 PSI, the air charge should be 38 PSI. If the pressure is low, use an air compressor to add air. If the tank feels heavy with water and there's no air pressure, the bladder may have failed and the tank may need replacement.