When your microwave won’t power up or won’t heat, you may rightly suspect that a fuse is blown. If the microwave won’t power up at all (the control panel doesn’t light up), the house fuse for the microwave may be blown or the house circuit breaker for the microwave may have tripped. (Older homes use fuses to protect appliance electrical outlet circuits and newer homes use circuit breakers.) Resetting the house circuit breaker or replacing the house fuse may restore power to your microwave. An internal fuse inside the microwave case can also prevent the microwave oven control from powering up. When the microwave has power but won’t heat or runs but won’t heat, a blown fuse is often the culprit causing the problem. To see whether your microwaves house fuse has blown (or its circuit breaker has tripped), unplug the microwave and plug a small electrical device such as a lamp or night light into the outlet to check for power. If the small electrical device doesn’t get power through the electrical outlet, then the microwave house fuse is likely blown (or its circuit breaker likely tripped). Replace the fuse or reset the tripped house breaker to restore power to the microwave’s electrical outlet. If the small electrical device powers up (indicating that the microwave’s electrical outlet has power) but the microwave doesn’t work, then a blown internal microwave fuse may be keeping the microwave from powering up or heating. Microwave ovens do require specific internal fuses. A microwave typically has several different types of fuses that perform various functions. The wiring diagram and replacement parts diagram for your microwave shows exactly which fuses your model has. Here are the different types of internal fuses that you’ll find in many microwave ovens. Line fuse. The line fuse blows when excessive electrical current flows through the microwave because of an electrical short in wiring or a microwave part. The microwave will be completely dead when the line fuse blows. Magnetron thermostat or fuse. The magnetron produces the high-energy waves that heat food inside the microwave oven cavity. When the magnetron overheats, the magnetron thermostat trips or the magnetron fuse blows to prevent fire and electrical shorts inside the microwave. The magnetron thermostat resets when it cools down on some microwave models. On some microwaves, the magnetron thermostat is non-resettable and must be replaced once it trips. A magnetron fuse isn’t resettable so it needs to be replaced after it blows. Cavity thermostat or cavity thermal fuse. The cavity thermostat or cavity thermal fuse rests on the top of the microwave’s oven cavity. The cavity thermostat (or fuse) trips when food inside the microwave oven cavity overheats and catches on fire. The cavity thermostat is resettable on some models so you can resume using the microwave once the oven cavity cools down and the thermostat resets. If the cavity thermostat is non-resettable or the microwave has a cavity thermal fuse, you’ll need to replace the component after it blows. To find out which fuse to use in a microwave, look up the part on the microwave parts list diagram for your specific model. Order the replacement part specifically listed for your model once you’ve located the fuse on the parts diagram. Although you can order a replacement fuse for your microwave, we strongly advise against attempting to replace an internal fuse yourself. Attempting DIY repairs on a microwave is extremely dangerous. The Consumer Product Safety Commission Safety Alert on DIY microwave repair warns against attempting microwave oven repairs because of the extreme risk of electrocution. Microwaves contain high voltage capacitors that retain a lethal amount of electricity even when the microwave is unplugged from its power source. Don’t risk your life or health by attempting to replace an internal microwave fuse on your own. Have a service technician replace the fuse or replace the microwave.How do I know if my microwave fuse is blown?
Does a microwave need a special fuse?
What fuse to use in a microwave?
FAQs
How To Replace a Microwave Fuse? ›
Although you can order a replacement fuse for your microwave, we strongly advise against attempting to replace an internal fuse yourself. Attempting DIY repairs on a microwave is extremely dangerous.
Can I replace a microwave fuse myself? ›Although you can order a replacement fuse for your microwave, we strongly advise against attempting to replace an internal fuse yourself. Attempting DIY repairs on a microwave is extremely dangerous.
Why is my microwave tripping the fuse? ›When an appliance such as a microwave oven repeatedly trips the circuit breaker, it's overloading the electrical circuit, which is rated to handle a finite number of amps.
How much does it cost to replace a microwave fuse? ›Repair Type | Average Cost |
---|---|
Diode Replacement | $55–$130 |
Microwave Fuse Replacement | $75–$200 |
Microwave Fan Repair | $75–$200 |
Touch Panel Repair or Replacement | $100–$300 |
In addition to the fuse blowing, installing a fuse with a different ampere rating could damage the wiring and cause a fire. Therefore, when replacing a fuse, it is best to use the same type of fuse, with the same ampere rating.
Can a microwave work without a fuse? ›When the fuse fails, power is interrupted to the controls of the microwave and it will become nonfunctional. The ceramic fuse is located inside of the cabinet near the entry point of the power cord. Remember to unplug the cord before attempting any repairs. You can check the fuse for continuity with a multi-meter.
Do all microwaves use the same fuse? ›Microwaves usually contain several types of fuses for safe operation. A main fuse or line fuse is a fuse that will cut the flow of electricity if too much current passes through it. Conversely, a thermal fuse will prevent electrical flow if the fuse is heated to a specific temperature.
What fuse to use in microwave? ›13A Fuse – washing machine, dishwasher, microwave, kettle, toaster, iron.
What does a burnt microwave fuse look like? ›The fuse holder is located two or three inches into the unit, and may be attached to a power board. Decide if your fuse is blown. A blown glass fuse will produce flash burn marks on nearby surfaces, or it will be completely black on the inside. The internal fuse wire (filament) will be melted and blackened.
Will a blown fuse cause a microwave not to heat? ›If the microwave stops heating, it is easy to think you may need a new microwave. However, in most cases, it will be easier and cheaper to identify and replace the defective part causing the issue. Typically, if the microwave is not heating, a door lock or blown fuse will be causing the issue.
Can I use a 15 amp fuse instead of 20 in the microwave? ›
Do you need a 20-amp outlet for a microwave? If it is a dedicated circuit, then yes. But if it is just plugged into any outlet in the room, then yes, you can use 20 or 15, but i depends upon the instructions from the manufacturer. See, most are fine on 15 amp outlets, but others are bigger and require 20 amps.
Can I use a higher amp fuse in my microwave? ›If you replace a fuse with a higher amp fuse, especially in an appliance that is not perfectly functioning, it can lead to serious consequences. While the appliance may initially continue to work, you are taking on increased potential risks.
Can you replace a fuse without an electrician? ›Replacing a fuse is a relatively easy, do-it-yourself home task that you can tackle with a little information and some electrical home safety savvy. If your home has a fuse box, the best advice is to plan ahead and become familiar with the electrical panel and with the types of fuses it requires.
Can you replace a blown fuse yourself? ›Remove the blown fuse. Unscrew the damaged fuse and replace it with a fuse of the exact same size, amperage, and type. Screw in the fuse in the same location. Restore power to the fuse box by flipping the main power switch.
Is it safe to fix your own microwave? ›DIY Microwave Oven Repair
Because microwaves use high voltages at high power, even after being switched off, the capacitator can hold enough charge to give you a dangerous shock. Take the safest path and hire a professional for any repairs to your microwave oven.