To troubleshoot an electrical circuit breaker, identify the initial electrical issue; for example, problems such as flickering lights or faltering electrical input to appliances may suggest problems with specific breakers. Failures in multiple areas of the home and loud humming noises may indicate a breaker overload. If symptoms do not point to an immediate cause, try unplugging appliances on each circuit to rule out an overload.
Check the wiring coming into the circuit breaker or around the allotted outlets for a problematic circuit. Loose or faulty wires could cause electrical issues that may seem related to the circuit breaker but in actuality are not symptomatic of any breaker problems.
If you suspect an overload, but no electrical overload is immediately evident, unplug several appliances, and reset the circuit breaker by switching it to off and then on again. Go through any suspected areas, and plug the appliances back in, keeping track of the watts or volts used by each appliance. Use this method to identify if there is a problem with the load of a given circuit. If the circuit overloads or turns off before it reaches the expected load threshold, it indicates a likely problem with the circuit and requires evaluation by a professional electrician.