GE Microwave Not Heating Food But Runs (What To Do)

I loved my GE microwave so very much. It had been reliable and always heated my food perfectly, until recently. A few weeks ago I tried to cook some Ramen noodles. Not the healthiest food, but I was in a hurry. I put it in for the usual 5 minutes and when the timer went off, to my surprise the food was still cold. I was left with cold food and confusion, so I turned to the internet. 

The most common reason a GE microwave may not be heating is due to a bad diode that burnt out. A less common reason is that the magnetron may have burnt out. Both of these issues can be resolved with a replacement part that can be purchased online. 

Since the microwave is one of the most convenient items in your home, I understand how important it is to get it back up and running. Below, I’ll go over some of the most common and uncommon reasons why your GE microwave isn’t heating your food anymore. Some fixes are quick and some are more complicated and should only be done by a professional. 

Is There A Reset Button On Your Microwave?

There is no reset button on a GE microwave. The only way to reset a GE microwave is to unplug it from the wall for 30 seconds and plug it back in. This will hard reset the microwave and you will now have lost any presets you had and you will need to reset the time. 

If the plug to your microwave can’t be reached, you can turn it off using the breaker in the fuse box. All you have to do is flip the breaker, wait 30 seconds, and flip it back to the “on” position. If there’s anything else on this circuit, it will also be reset. 

If your microwave still isn’t heating, there are a couple of reasons why this could be happening. 

Top Reasons Why Your Microwave Is Not Heating Up

Is It on “Timer”?

I’ve made this mistake more than once. I thought that I was cooking something when I was actually using the timer mode. 

If you accidentally set the timer instead of the microwave, it will look like your microwave is running, but it’s really not. It’s just the clock counting down like it would when it’s cooking. If the timer is on, simply click the “clear” button on your microwave to reset the function. 

Door Isn’t All the Way Closed

The microwave needs to be completely shut in order to work properly. If you can’t enter anything into the function bar or your microwave just isn’t working, check to ensure the door is actually closed. If it’s not, you’ll notice the light remains on and the microwave won’t do much of anything. 

High Voltage Diode Defect

This is the most common cause of microwave not working. The high voltage diode converts power from A/C to D/C. This is what provides energy to the magnetron to heat the microwave and anything inside of it. Since the magnetron or diode malfunctions, they both serve the same purpose. If one goes out, neither of them will work. 

High Voltage Diode

Door Switch Defect

A GE microwave has multiple switches that ensure the door is closed. If one of them isn’t working correctly, the microwave won’t recognize that you’ve shut the door. 

If the door is open, you can’t perform any functions on the microwave. Most microwaves won’t even let you enter a cook time into it unless the door is closed. 

Burnt Out Megnetron

The magnetron works with the diode to heat the microwave. If one or theother is burnt out, your microwave won’t heat as it should. It uses high voltage, high current DC power to generate the microwave frequency that heats the food. Unfortunately, it’s not repairable, it has to be replaced. 

Burnt Out Capacitor

The high voltage capacitor also works with the diode to convert the output of the transformer to the DC voltageand to double the output voltage. If this is burnt out, the whole circuit will stop working and the microwave won’t heat up. 

Broken Transformer

Microwaves produce high voltage in order to power the magnetron antenna, which is what cooks the food. They also have transformers. If a transformer fails, it will arc and emit a burning smell. This will tell you that the microwave needs to be repaired. 

Blown Thermal Fuse

If the microwave were to overheat, the thermal fuse would cut off power to it. If a thermal fuse has blown it needs to be replaced rather than repaired.

Tripped Thermoprotector

The thermoprotector serves the same purpose as a thermal fuse. If the microwave overheats, it cuts the power off to it. Ifthe thermoprotector trips, the microwave won’t start or heat. 

Defective Main Control Board

This is rarely the case, but the main control board could be at fault. If the main control board is bad, you most likely won’t be able to perform any function on the microwave’s panel. If you think one of these may be the issue, there are steps you can take to test them. 

How To Test Each Component

*Note: Since microwaves contain high voltage, it’s recommended that you hire a professional to perform the testing and repair. 


Before you begin, unplug the microwave so that there’s no power going to it. You will then need to remove the cabinet to access the diode and discharge the high-voltage capacitor. 

You discharge the high-voltage capacitor by creating a short circuit between each of the two terminals. Touch the blade of a well-insulated screwdriver to one terminal and slowly slide the screwdriver forward until it reaches the other terminal. You will hear a loud “POP”. 

You can then test the diode with a multimeter to check for continuity. If there’s no continuity in one direction, the diode will need to be replaced. The replacement for this ranges from between $5-$25 for the part and $50-$100 for the labor

Door Switches

To test the door switches, first, unplug the microwave. Once you do this, access the switches by removing the cabinet. You will then need to remove each door switch. 

To test them, use a multimeter. This should reveal continuity. If there’s no continuity, one of the switches needs to be replaced. 

The replacement for this ranges from $50 to $100 including parts and labor. 


To test the magnetron, you will need to first unplug the microwave. You can access the magnetron by removing the cabinet. Once you do that, you need to discharge the high-voltage capacitor. You will follow the same steps outlined for testing the diode. 

Once you do that, you can test it with a multimeter. You should have a result of 2 to 3 ohms of resistance and continuity. If you see anything different, you need a new magnetron. 

Since the magnetron is the power source for the microwave, replacing it is going to be pricey. You can expect to pay $50-$100 for the part and $50 to $100 for the labor.


Testing the capacitor is the same as testing the diode and magnetron. You will need to unplug your microwave, access the capacitor by removing the cabinet, and discharge the high-voltage capacitor. 

Use an ohmmeter, test the capacitor. You should have a reading of infinity. If not, a replacement is needed. It costs between $50-$100 in labor and another $25-$100 for the part itself. 


Begin by unplugging the microwave, removing the cabinet, and discharging the high-voltage capacitor. Once you do this, locate and disconnect the six transformer wires. Unscrew the mounting screws and remove the old transformer. 

Attach the new transformer by screwing it in with mounting screws and attaching the new wires to the proper ports. 

On average, the cost to replace the transformer is between $100-$300 including parts and labor. 

Thermal Fuse

To replace the thermal fuse, unplug your microwave and remove the screws that secure the grill in place. Slide it to the left and remove it. 

Lift the control panel up and forward to gain access to the thermal fuse. You will disconnect the thermal fuse wires, unscrew the mounting screws, and remove the old fuse. Attach the new fuse by screwing it in with the mounting screws and attaching the new wires to the proper terminals. 

Slide the grill back in place and replace the screws. 

You can expect to shell out between $50-$100 for a new thermal fuse including labor.


Begin by unplugging the microwave and removing the cover. It may require you to completely uninstall your microwave if it’s a built-in unit. Avoid the high voltage capacitor. 

Remove the screws that keep the air duct assembly in place and move it out of the way to gain access to the thermoprotector. Disconnect it and remove it from the retaining tabs. You can now attach the new thermoprotector by placing it under the retaining tabs and connecting the new wires. 

Replace all screws that secure the air duct assembly and reinstall the microwave. 

The average cost for this repair is between $100-$300 for parts and labor. 

Main Control Board

To begin, unplug the microwave. Open the microwave door and remove the screws that keep the grill in place. Slide the grill to the left and remove it. You will also need to remove the mounting screws and grounding wire screws. 

Locate and detach the ribbon connector then remove the old main control board. Attach the new one by reconnecting the ribbon connector and replacing the screws. Replace all grounding wire and mounting screws. 

Put the grill back in place and replace the screws. 

You can expect to pay between $100-$300 in parts and labor for this repair. 

You can avoid these issues by following proper microwave maintenance tips. 

Proper Microwave Maintenance

Microwaves are certainly cheaper to replace than other larger appliances. Even so, it’s important that they’re properly maintained to keep them lasting longer and hassle-free. 

It’s important to keep the inside of it clean. Regularly wiping out the inside of the microwave can cut down on odors and keep corrosion from developing. Food that’s left in the microwave will constantly cook and will absorb energy that’s supposed to help heat current food, making it less efficient. 

You can avoid splatter inside of your microwave by using covers on your food. Microwave-safe plastic covers over your food will keep splashes from happening. 

You should also wipe down the outside of it. Dust, grease, and other residues can build up on the controls. It won’t necessarily damage anything, but it will leave the microwave unsightly and sometimes a little smelly. 

Lastly, never put metal in your microwave. The waves emitted from the oven will bounce off metallic materials, which can cause a fire or combustion. 

GE Microwave Troubleshooting

GE Microwave Not Heating But Running

If you’re sure your microwave turns, this can eliminate issues such as a bad power cord or outlet. The issue is most likely due to a bad diode or magnetron or both. Since they’re the main components responsible for heating food, they’ll need to be replaced. 

Another issue to consider is that you’ve accidentally turned on the timer instead of the microwave. It’ll make it look like your microwave is working, but it’s not. The microwave won’t heat anything. All it’s doing is counting down whatever time you entered into the control board. 

Sometimes, the turntable could be the problem as well. 

Turntable Not Turning

If your turntable isn’t turning, there could be a couple of reasons for this. The most common reason is that there’s an issue with the turntable motor. You will need a multimeter to check this. Here’s how to test that: 

  • Unplug the microwave
  • Remove the turntable and support ring
  • Remove the screws from the back side of the microwave
  • Disconnect the wire harness
  • Set the lower panel aside
  • Using a flathead screwdriver, pop off the terminals to the turntable motor wires
  • Connect the terminals with the terminals of the multimeter and check for continuity
  • If you don’t see continuity, the motor needs replacing. 

If the motor is fine, it could be a drive coupling problem. You will need to pull the coupling off the drive motor shaft to inspect it for damage. If there’s damage, it needs to be replaced. 

If the drive coupling seems to be in working order, check the glass tray support. Pull out the drive motor shaft to inspect the tray support for damage. If it’s damaged, replace it. If that’s not the issue, check the roller guide. 

The roller guide is the part that lies directly under the glass tray to rotate it, keeping it on track. The easiest way to check for an issue is to remove the roller guide and inspect it for cracks, damage, or wear. If it’s broken, it won’t work properly and the turntable won’t turn. 

If all else fails, check for an obstruction that could be stopping the turntable motion. Sometimes certain particles can get stuck under the turntable and will obstruct its motion. You will need to clean the turntable properly and anything underneath it. You can use warm, soapy water.   

Not Heating But There Is A Burning Smell

If you notice your microwave isn’t heating but you can still smell something burning, it’s probably an issue with the rectifier (diode). The rectifier is just another term for the diode. It’s what’s responsible for heating the microwave. 

It converts the A/C power output of the transformer to D/C, doubling the voltage to 5,000 volts. If this burns out, the magnetron won’t receive enough voltage to operate. When the diode fails, you will smell something burning because it’s trying to work, but can’t. 

There could be a variety of electrical issues that could cause the burning smell as well. It could be the magnetron,  high voltage capacitor, high voltage transformer, thermal fuse, thermoprotector, or even the main control board. Each one of these can be tested using the methods I’ve outlined above. 

Consult Yoru Brands FAQ Page or Support For Further Assistance

Today, there are multiple ways you can get in touch with GE customer support. The most common way to get in touch with them is to contact their toll-free number which is 800-626-2005. You can also email their customer service center if you’re not too worried about your microwave. 

If you need to get ahold of them but don’t want to call, they have a chat feature that allows you to chat with an agent regarding your issue. 

In addition to this, you can use their webpage to search for replacement parts. You can also access their FAQ page which can help you diagnose the issue with your microwave. 


As you can see, there are plenty of reasons why your microwave may not be heating correctly. It could be something as simple as the timer being activated on accident or something as complex as a bad control board. 

Sometimes it can be hard to tell what the issue really is until you’ve completed some troubleshooting steps. It’s recommended that you consult a professional before touching your microwave if you’re unsure about the steps since it contains high-voltage electricity. 

It’s my sincere hope that the information above helped you diagnose the issue with your GE microwave. If your microwave is still under warranty, you may be able to get it repaired at no cost to you and you won’t even have to touch it.