My microwave and toaster are on two separate sockets, so why can't I run both at the same time without tripping the breaker?  - Angie's List member Patricia Spadafora

The problem is that although the appliances are plugged into separate sockets, they're on the same circuit, which overloads it when used together, according to Paul Fattizzi of highly rated Paul Fattizzi Electric Inc. in White Plains, N.Y. "If your outlets are on a 20-amp circuit breaker, and you're running a 12-amp toaster and a 12-amp microwave at the same time, that's a 24-amp load. It's not going to work," he says.

Fattizzi says modern electrical code mandates that each major kitchen appliance should be powered by its own dedicated circuit. He recommends installing a new circuit dedicated to the microwave, which he estimates would cost $225 to $325.

Regularly tripping the circuit breaker can create a fire hazard, says Elvira Ceriello, owner of highly rated Ceriello Electric in Brooklyn, N.Y. "With time, the wires will burn and melt," she says. Fattizzi advises that circuits generally last longer when they're not consistently overloaded. "If you're running a coffee pot 24 hours a day, [the circuit] will run out sooner," he says. "It's like driving a car at 100 miles an hour all the time; the engine won't last forever."

Modern appliances demand much more electricity than what the outdated electrical systems commonly found in older homes can handle, so Fattizzi recommends upgrading the main service panel from 100 to 200 amps if possible. He estimates the project would likely cost $2,300 to $2,500.