Fuses prevent the excess flow of electrical current. Typically, older homes have fuse boxes. Excess electrical current passing through a fuse causes the thin metal wire that looks like a light bulb filament to overheat and melt, which opens the circuit. Fuses come in several types including a plug fuse and cartridge fuse, which are the two most common. Most homeowners, at some point overload the electrical capacity of the fuse and need to replace it when no power is present in an outlet.
Plug Fuse - Turn the light switches to the off position and unplug all devices from the receptacles in the room with power loss.
Open the front door of the fuse box to gain access to the fuses.
Examine the fuses to find the one that appears brown near the center or the one where the thin metal wire in the center is no longer in one, arced piece.
Turn the fuse to the left to loosen it and remove it from the fuse box. Place a new fuse with the same amperage in the fuse box. Turn the fuse to the right to tighten it.
Cartridge Fuse - Disconnect all electrical devices and turn off light switches to the room without power.
Open the front panel on the fuse box. Locate the appropriate pull out block, which is a square device that houses cartridge fuses and pull it out of the fuse box. As soon as you remove the pull out block, the entire house is without power. If the cartridge fuse is for a dryer or other large electrical appliance, it may have its own wall-mounted box that is not removable. Locate the box for the device, open the front door and slide the power cutoff lever to the off position.
Grip the middle of the cartridge with a fuse puller and pull it from the box.
Position the replacement fuse up to the spring clips that hold a cartridge fuse in place and press it into the grip of the spring clips with the fuse puller.
Turn the power lever back on or place the pull out block back into the fuse box.