How to Fix a Blown Fuse: 6 Steps to Get Your Power Back in a Flash
Fixing a Blown Fuse at a Glance
- Tools & Materials: Fuse, multimeter, pliers or fuse puller
- Step 1: Turn off lights and appliances
- Step 2: Find fuse box
- Step 3: Turn off power
- Step 4: Find blown fuse
- Step 5: Replace fuse
- Step 6: Restore power and test
When the power goes out in your home, the first thing you should check is if you blew a fuse or tripped a circuit breaker. Despite the fact that the terms “fuse” and “circuit breaker” are often used interchangeably, they’re actually two completely different components.
While most modern homes are equipped with circuit breakers in their electrical panels, homes built before the 1960s might have fuses instead. Although replacing a blown fuse isn’t as simple as fixing a tripped circuit breaker, replacing a blown fuse is a relatively simple task that’s well within the capability of most homeowners.
So if your home’s equipped with fuses, and you need to restore power ASAP, read on to learn how to fix a blown fuse in six simple steps.
How to Fix a Blown Fuse
Things You’ll Need:
- New fuse
- Multimeter or continuity tester (optional)
- Pair of pliers or fuse puller (optional)
1. Turn Off Lights, Switches and Appliances
Even though the power will be off in the section of your home the blown fuse controls, turning off all the lights, wall switches and appliances plugged into wall outlets in the part of your home that lost power is a necessary first step. Since your fuse may have blown because a particular electrical component — or combination of components — placed an excessive electrical demand on that circuit, replacing your fuse with the same electrical demand in place may cause the new fuse to blow as soon as it’s installed.
2. Find Your Fuse Box
Locate where your fuse box is installed. The fuse box will be a square or rectangular box (often gray in color) that will usually be located in your garage, basement, attic, laundry room or utility room.
What’s Inside Your Fuse Box?
Open the fuse box’s cover door and take a look inside. There will often be two types of fuses: cartridge and screw-in fuses.
Cartridge fuses are cylindrically shaped with two metal caps on both ends. These are often used for the main fuse that powers your entire house, along with larger appliances, like washers and dryers. Cartridge fuses are housed in a square or rectangular fuse block that can be removed by pulling on the handle on the front of the block. Once the block is taken out of the fuse box, the cartridge fuse can be removed with a pair of pliers or a specialty fuse puller. Replacing a cartridge fuse isn’t usually necessary unless you’ve lost power to your entire home, or to a single high-demand appliance with its own designated circuit.
Screw-in fuses are circular and have a threaded base that screws into the fuse panel. The tops of these fuses are equipped with a glass viewing window that allows you to see the internal metal strip that’s designed to melt under a high electrical demand to stop the flow of electricity to that circuit. Screw-in fuses are often used for electrical appliances with lower electricity consumption, like wall outlets and lights. These are the variety that blows most commonly.
3. Turn off the Power
Before inspecting or removing any fuses, shut off the power to the entire box by pulling out the main fuse block from the panel. The main fuse block should be clearly marked inside the panel. If not, it will usually be the largest block and located at the very top of the box. If you have lost power to your entire house instead of an individual section, the cartridge fuses inside this main block should be inspected (and replaced, if necessary) first.
4. Find the Blown Fuse
The fuse that controls the area of your home that lost power should be clearly labeled inside the box. Otherwise, you will likely have to inspect each fuse individually. Inspect the fuse or fuses for any noticeable signs of damage, like the metal strip being melted or the glass being scorched. If you can’t tell which fuse is blown from a visual inspection alone, you might have to rent, borrow or purchase a multimeter or continuity tester to test the continuity of each fuse.
5. Replace the Fuse
Once you’ve found the blown fuse, remove it from the box. Take the fuse down to your local hardware store and purchase a replacement fuse with the same amperage rating. This rating should be clearly labeled on the front of the fuse. Using a fuse with a higher or lower amperage rating than what the circuit is rated for can cause potentially serious — and even dangerous — electrical problems.
Once you’ve acquired your new fuse, install it in the box by reversing the steps you took to remove the old one.
6. Restore Power and Test
Place the main fuse block back into the box, and verify that power was restored to the affected section of your home by turning on the lights. Next, progressively turn your remaining wall switches and appliances back on. If the new fuse blows after plugging in a certain appliance, you can be fairly certain that it was responsible for overloading the circuit and blowing the fuse. Move or remove that appliance and replace the fuse again to see if that fixes the problem.
When to Call a Professional
If your new fuse blows immediately after installing it, or blows shortly after despite eliminating any high-demand electrical appliances that you may have initially suspected to be the culprit, you may have a more serious electrical problem going on. The underlying issue may be a short circuit, a ground fault or an arc fault. In any case, you will likely need to hire a professional electrician to inspect and correct it.