How to Fix a Blown Fuse

Fixing a blown fuse in your home is a simple, do-it-yourself project that can be easily completed with the right tools, knowledge, and safety precautions. From helping you locate your electrical box and identifying if you have fuses or circuit breakers, to the safety basics and steps to fixing a blown fuse, we’ll show you how to get the power back on.

How to locate your fuse box 

The first step to fixing a blown fuse is to locate your electrical box. Older homes will typically have a fuse box, whereas homes built after 1965 or those that have been remodeled will have a circuit breaker box. Both the fuse and circuit breaker boxes work to protect against circuit overloads and short circuits by tripping an overloaded circuit and cutting power to the circuit.

While it may be an inconvenience when it happens, a tripped circuit helps protect your home from a fire caused by an overloaded circuit.

Here are some common areas the electrical panels are located in:  

• Garage 
• Attic 
• Basement 
• Storage room 
• Laundry room 
• Utility room 

Some older homes may have their panels outside near the electric meter box. If you still cannot locate it in one of these areas, refer to your home inspection report, or ask a professional electrician for help.  

Safety precautions before you start

A few safety items you need to complete before you start working within the fuse box.   

• Turn off all lights and unplug some of the electrical appliances in the room that lost power. If you were using a specific appliance such as a hair dryer, vacuum, microwave, or other large, energy drawing appliance when the power went out, that appliance probably caused the fuse to blow. If you leave it plugged in and on when you replace the fuse, it will immediately overload the circuit and blow it again.
• Make sure your hands are dry and that you’re standing on a dry surface wearing rubber sole shoes when working in the fuse box.
• If you have concerns for your safety and don’t feel comfortable working with a broken fuse, stop and contact a professional electrician. Saving a few dollars isn’t worth compromising your personal safety.

What does a blown fuse or a tripped circuit look like?

Circuit breakers look like switches while fuses are round and screw into sockets. Fuses have glass windows with metal wires inside. A blown fuse may contain melted metal inside, there may be burn marks on the glass, or the glass may have become discolored. 

A tripped circuit is a bit easier to identify because the switch will be flipped. Examine the switches and locate the switch that has flipped to the center, in between the on and off position.

6 steps to fix a blown fuse or tripped circuit 

Once you’ve located your blown fuse, there are a few steps for changing the fuse and turning the power back on. To complete this job, you’ll need a flashlight and a new fuse that’s the exact same size, amperage rating, and type as the blown one.

If you aren’t sure you have the right fuse, bring the blown one to a hardware store for them to match. It’s very important to have an exact match because using one with a higher amperage can damage the entire wiring of your home and any connected appliances.

1. Turn off the main power to stop the electrical flow to the fuse box.  
2. Locate the room, hopefully previously marked, where the outage occurred.  
3. Examine the fuses and circuits, looking for the blown one as described above.  
4. Unscrew the blown fuse and replace the fuse with a new one.  
5. For circuits, flip the tripped circuit from the center position to the off position, and then flip it back to the on position.
6. Turn the main power back on.

Once you’ve replaced the fuse or flipped the circuit breaker back, test the lights in the room that lost power. Try one or two appliances at a time—don’t overload the fuse by using too many at once or you’ll end up with another blown fuse. If you’ve followed these steps, and the blown fuse won’t reset, consider contacting a licensed professional for help.

How to prevent blown fuses 

If fuses keep blowing in your house, there are a couple of things to look at to prevent future problems.  

Overloaded circuit 

An overloaded circuit is the most common reason for a fuse to blow and one of the easiest home repairs to fix in your home. When a circuit is overloaded, the breaker will trip as a safety precaution to protect the rest of the wiring in your home and prevent a house fire.

If you’re consistently overloading a circuit, you may need to move some high-demand appliances to other rooms of the home so that you don’t overload the circuit. You may also consider upgrading your home circuits to meet the electrical demand of your home.

Short circuit, ground fault, and arc fault 

Each of these wiring problems are related to the wiring in your home and are more serious reasons for a fuse to continue to blow. If you find that you’re continuing to blow the same fuses and have moved high-energy drawing appliances to other outlets, it’s best to contact a licensed professional to diagnose and fix these electrical problems.

Additional tips to help you fix a blown fuse

Here are some additional tips to consider the next time you need to fix a blown fuse: 

• Label the circuits and fuses with the corresponding room in your home to make it easier to identify when a circuit trips.
• Don’t block the fuse box with furniture and other boxes—you need easy, unobscured access to it to fix the problem.
• Keep a flashlight next to the circuit box so that you can locate the problem easily. 
• When you buy your home, take the time to find your fuse box and determine the fuse type and size you need.
• Purchase a few fuses to have on hand so that when a fuse blows, you can easily replace it without having to run out to the hardware store at an inopportune moment.

Additional Resources