A microwave fuse is a safety device that cuts power if something goes wrong inside the unit
When a microwave stops working suddenly, a blown fuse is often the culprit. The fuse is a small cylindrical component, usually located near where the power cord enters the microwave, that protects the internal circuits from electrical damage. If the fuse has blown, replacing it is a straightforward repair you can do yourself in about 15 minutes — but you must unplug the microwave first and follow the steps carefully, because the capacitor inside can hold a dangerous electrical charge even after unplugging.
A fuse blows when too much electrical current flows through it, which happens when a component inside the microwave fails or shorts out. Unlike a circuit breaker in your home, a microwave fuse does not reset — once it blows, it must be replaced. If you replace the fuse and it blows again when ready, the microwave has an internal problem that needs professional repair.
Key Takeaways
- Always unplug the microwave and wait at least five minutes before opening it, because the capacitor holds a charge that can cause injury.
- The fuse is a small cylinder, usually 1 to 2 inches long, located in a holder near the power cord entry point or on the control board.
- You need to know the fuse's amperage rating (printed on its surface) to buy the correct replacement at a hardware store or online.
- If the new fuse blows within a few days, the microwave has an internal fault and should be serviced by a technician.
Locate the fuse before you begin
The fuse location varies by microwave model, so check your owner's manual first — it will show you exactly where to look. In most microwaves, the fuse sits in a small plastic holder mounted on the control board or near the power cord entry point on the back or side of the unit. Some models have the fuse holder on the front panel behind the control buttons.
If you do not have the manual, search online for "[your microwave brand and model number] fuse location" and you will usually find a diagram or video. The model number is printed on a sticker inside the microwave, on the back, or under the unit. Write down the model number before you start — you will need it to order the correct replacement fuse anyway.
Unplug the microwave and discharge the capacitor safely
Unplug the microwave from the wall outlet. Wait at least five minutes. This waiting period is not optional — the capacitor inside stores electrical energy and can deliver a painful or dangerous shock even when the unit is unplugged. Waiting allows the charge to bleed off naturally.
Do not touch any large cylindrical components inside the microwave, especially if they have wires attached. The capacitor is usually the largest component you will see, and it looks like a metal can. If you are uncertain about what you are looking at, take a photo and show it to a technician before proceeding.
Remove the fuse and note its amperage rating
Open the microwave cabinet or panel to access the fuse holder. The holder is usually a small plastic clip or socket that holds the fuse horizontally or vertically. Gently pull the fuse straight out of the holder — it should come free with light pressure. Do not force it.
Look at the fuse itself. The amperage rating is printed on the metal end cap or along the cylinder — it will be a number like 15A, 20A, or 25A. Write this number down. You must buy a replacement fuse with the exact same amperage rating. Using a fuse with the wrong rating can damage the microwave or create a fire hazard.
Buy the correct replacement fuse
Take the amperage rating to a hardware store, or search online for "microwave fuse [amperage]A" — for example, "microwave fuse 20A". Microwave fuses are inexpensive, usually between $3 and $8 each. You can also order the fuse by your microwave's model number from an appliance parts website; the parts site will confirm the correct fuse for your unit.
Make sure the replacement fuse is the same physical size as the original. Most microwave fuses are about 1 to 2 inches long and roughly the diameter of a pencil. If the replacement looks significantly different in size or shape, double-check that you have ordered the right part.
Install the new fuse and test the microwave
Insert the new fuse into the holder, pushing it straight in until it seats firmly. You should hear or feel a small click. Do not force it — if it does not slide in smoothly, remove it and check that you have the right size and that the holder is not bent or damaged.
Plug the microwave back in and turn it on. Set it to run for 30 seconds on high power with nothing inside. If the microwave starts and runs normally, the fuse replacement was successful. If the microwave does not turn on or if the new fuse blows when ready, unplug it and stop — the microwave has an internal problem that requires professional service.
When to call a technician instead
If the fuse blows again within a few days or a week, do not keep replacing it. A repeatedly blown fuse means something inside the microwave is drawing too much current, and that component needs to be repaired or replaced by a technician. Continuing to replace the fuse will not solve the underlying problem and may damage the microwave further.
If you are uncomfortable opening the microwave, unsure about the capacitor, or uncertain which fuse to buy, a microwave repair technician can replace the fuse for you in about 30 minutes. The service call usually costs $75 to $150, depending on your area and the company. For older microwaves, this cost may be close to the price of a new unit, so weigh the repair cost against replacement before you decide.
Frequently Asked Questions
Can I use a fuse with a higher amperage rating if I cannot find the exact one?
No. A higher-amperage fuse will not blow when it should, which means the microwave's circuits will not be protected if something goes wrong. This can lead to fire or damage to the unit. Always use the exact amperage rating printed on the original fuse.
What does it mean if the fuse blows right after I replace it?
It means the microwave has an internal electrical fault — a component is short-circuiting or drawing too much current. Unplug the microwave and do not use it. Continuing to replace the fuse will not fix the problem and may cause a fire. Contact a repair technician.
Is it safe to replace the fuse myself, or should I always call a technician?
Replacing the fuse is safe if you unplug the microwave, wait five minutes, and avoid touching internal components other than the fuse holder. If you are uncomfortable working inside the microwave or unsure about the capacitor, a technician can do it quickly and inexpensively.
Where can I buy a microwave fuse?
Hardware stores like Home Depot and Lowe's stock common microwave fuses. Appliance parts websites like PartSelect and AppliancePartsPros let you search by model number. Amazon also carries microwave fuses. Bring the amperage rating or model number with you to may support you get the right part.