What makes a microwave go bad?

Author: Prof. Keshawn Wilderman PhD  |  Last update: Tuesday, March 4, 2025

Issues with the door switch, internal fuse, magnetron, diode, high-voltage capacitor, and electronic control board are common causes of microwave malfunctions, requiring repair or replacement by a technician.

What is the most common cause of microwave failure?

Misset functions or broken parts are often to blame when your microwave is not heating up. Settings like Control Lock Mode, Demo Mode or power levels set too low may be preventing food from cooking, or more complex causes like a broken magnetron, door switch or high voltage diode could be the source of the problem.

How can you tell when a microwave is going bad?

Smoke, sparks, and burning odor are the primary signs that signal the last days of a microwave. Other problems like unexplained loud noise, prolonged or faster cooking, loose door hinge, and malfunctioning keypad are signs to invest in a new microwave.

How long do microwaves normally last?

The average microwave oven lasts about seven years with normal use, yet even less with heavy use and poor maintenance. A large family may find themselves replacing their appliance every four to five years as they become more reliant on its use to heat snacks and leftovers or to defrost meals.

What causes a microwave to go bad?

It may be a damaged power cord, a bad fuse, or a malfunctioning circuit board – all of which are issues with the microwave itself. This microwave failure may also be from a natural cause. Have there been any power surges or storms near you? That can cook the wiring in your appliance.

Top Reasons Microwave Is Not Heating — Microwave Oven Troubleshooting

What usually breaks in a microwave?

Understanding the most common parts that can break in a microwave, such as the magnetron, door switches, turntable, control panel, and high voltage components, can help users identify issues early and seek professional repairs or replacements.

Why would the microwave suddenly stop working?

Reasons: Control panel issues: A malfunctioning control panel can prevent the microwave from responding to your inputs. Fuse problems: Blown fuses can interrupt the power supply to the microwave. Power cord damage: A damaged or disconnected power cord can prevent the microwave from receiving power.

When should you throw out your microwave?

On average, microwaves last 7-8 years.

Is it worth fixing a microwave?

If the cost of repairing a microwave comes close to or exceeds the price of a new one, it might make more financial sense to replace it. However, if the costs of repairing are relatively low and the microwave isn't too old, it could be worth repairing the microwave.

What is the best microwave brand?

As the best microwave overall, we chose the Panasonic Microwave Oven; it combines a 1,200-watt motor with a compact exterior. If you're looking to save money and space, the Commercial Chef Countertop Microwave is the best budget microwave: simple but effective, much like microwave cooking itself.

What causes a microwave to burn out?

The most likely cause is that the diode, which increases the voltage to the magnetron, has burned out. If this is the case, then the magnetron can't receive enough power to generate microwaves. These can usually be replaced for a low cost.

What are the symptoms of a bad magnetron in a microwave?

One of the most common issues with a malfunctioning Magnetron is the lack of heating. If your microwave is running but not producing heat, it could be due to a faulty Magnetron, burned-out filament, or a malfunctioning high-voltage diode.

How to test your microwave?

Heat the water for exactly 2 minutes and 30 seconds on the High power level. The High power level is the default heat setting on the Microwave. A temperature rise in the range of 28 to 40 degrees Fahrenheit (15 to 22 degrees Celsius) indicates that the Microwave oven is heating/cooking properly.

How do I know if my microwave is dying?

When to replace the microwave? Common signs that your microwave needs changing
  1. Making funny noises.
  2. Smells like electrical burning.
  3. Isn't cooking food in the usual time or cooking unevenly.
  4. Needs help to work properly – such as a spoon to hold the door closed.
  5. Keypad has stopped working.

What damages microwaves?

Generally, metal pans or aluminum foil should also not be used in a microwave oven, as the microwaves are reflected off these materials causing the food to cook unevenly and possibly damaging the oven. The instructions that come with each microwave oven indicate the kinds of containers to use.

How much does it cost to fix a microwave?

Repair versus replace

Ilya Uvaydov, owner of Urban Appliances Repair in Daly City, California, says the only microwaves he typically repairs are high-end models made by Viking, Thermador and other luxury brands. The cost to fix these units ranges from $200 to $600, depending on the problem.

What is the life expectancy of a microwave?

The average microwave oven lasts about seven years with normal use, and even less with heavy use and poor maintenance. A large family may find themselves replacing their appliance every four to five years as they become more reliant on its use to heat up snacks and leftovers, or to defrost meals.

What is the common problem with a microwave?

Issues with the door switch, internal fuse, magnetron, diode, high-voltage capacitor, and electronic control board are common causes of microwave malfunctions, requiring repair or replacement by a technician.

How much does it cost to replace a magnetron in a microwave?

Magnetron Replacement

The magnetron is the heating technology that powers your microwave. Without it, your food is as good as cold. Replacing a microwave magnetron costs between $100 and $200 on average.

Why are people ditching microwaves?

"Microwaves alter the taste of food, take up a lot of room and make nearly everything mushy," she says. Nicole Robina, a publicist, agrees with Shortt that conventional ovens are the way to go. "Everything tastes better when you heat it up in the oven," she says. "It's worth the extra time."

Where to throw away a microwave?

Take Your Microwave to an Electronic Waste Recycling Center

If your local recycling center doesn't accept appliances, you can check with an environmental conservation group such as GreenCitizen, which accepts mail-ins. Send your microwave to them and they will recycle it for you for a small fee.

What happens when a microwave goes bad?

If the inner case is damaged, rusted, with holes, or not making a perfect seal with door, radiation can leak. This is dangerous to humans. Also, if the damage is severe, the magnetron gets very hot and fails. Or in rare cases, the power supply may catch fire.

Can a microwave get too hot and stop working?

If the Microwave is overheating and shutting itself down, this is caused by high voltage parts inside the unit getting too hot the leading the thermal cut-out switch to be activated as a safe feature to prevent further overheating.

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