Many homeowners want to handle more of their own well and treatment equipment, and some of it is reasonable. The line to draw is simple: anything you can do without opening a live electrical box is usually fine to learn, and anything inside the pump power circuit should go to a licensed professional. Make that decision before a problem makes it for you.
Checks that are reasonably yours
With the system running, read the pressure gauge at the tank and at a tap. Watch how often the pump starts and stops during a normal draw. Look for drips at fittings and around the tank base. If your system has an inline screen, follow the manufacturer's instructions to clean it. Replace filter cartridges on the schedule the maker lists, and keep a note of the date and the part number you installed.
Where the line is
The pressure switch box, the control box, the pump wiring, and any capacitor are connected to line voltage. Do not assume a breaker is correctly labeled. Turn off power at the source, then confirm with a meter that the circuit is dead before you touch anything. Even with the pump off, a switch can carry power, so treat every wire as live until tested.
Settings should be written down
The pressure switch sets when the pump starts and stops. If those settings are wrong, the professional should adjust them and record the numbers on the invoice. Ask for the cut-in and cut-out values in writing. Without them, the next technician has to guess.
Stop and call if you see these signs
Stop work and call a professional if you see scorched or discolored wire, smell burning, notice the breaker trips more than once, hear the pump running with no water flowing, or find water near the electrical box. Shut the system down if the pump cycles rapidly. These are signs of a problem that can get worse quickly.
Questions to ask the professional
Ask whether the person is licensed for electrical and well work where you live. Ask whether any required permit will be pulled and who pulls it. Ask whether they will measure pump performance and pressure after the work, not just confirm the pump runs. Ask what they will record on the invoice. Local rules on well pump work and permits differ, so check with your county or city building office if you are unsure what applies to your property.