Microwave Not Heating Food But Still Runs

A microwave oven not heating food but still running is generally caused by a faulty magnetron, a broken door switch, or other hardware-related problems. 

So now that we have summarised the main cause, let’s get into identifying the issue.

Identifying Common Problems:

1. Faulty Magnetron:

The magnetron is the component responsible for generating the microwaves that heat your food. If it’s broken, your microwave will still run but won’t produce any heat. The telltale signs of a faulty magnetron include the microwave running without heating, unusual noises like humming or clicking, and visible damage to the magnet or metal cylinder.

Possible Solution:

If you suspect, it’s a faulty magnetron check your user guide by unplugging the microwave and removing the side panel to access the magnetron. Discharge the capacitor and disconnect the wires from the old magnetron.

Install the new magnetron, ensuring it matches the model of your microwave. Reattach the wires and put the side panel back in place.

If it’s not a faulty magnetron, then move on to the next common problem

2. Broken Door Switch:

The microwave door switch is responsible for preventing the microwave from operating while the door is open. If the switch is broken, your microwave may run but won’t generate any heat.

Symptoms of a faulty door switch include the turntable not rotating and the microwave light failing to illuminate when the door is opened.

Possible Solution:

First, unplug the microwave, and then remove the control panel. Disconnect the wiring and unscrew the switch assembly. Take note of the connections before removing the old switch.

Next, test the defective switch or look for signs of damage. Usually, you can tell is its cracked or broken, and the door does not shut properly. If you find the switch to be faulty replace it with a new one that matches the brand, number of terminals, and open/closed configuration. Make sure you reassemble the microwave by connecting the wiring and securing the necessary screws.

3. Malfunctioning High Voltage Diode:

The purpose of a high voltage diode is to supply power to the magnetron, enabling it to generate microwaves for heating. If the diode is defective, your microwave will run but won’t heat the food.

Possible Solution:

Start by unplugging the microwave and removing the control panel. Look for the capacitor and remove the capacitor and unscrew the diode from the frame. Carefully install the new diode by connecting it to the terminal on the capacitor using pliers. Secure the other side of the diode to the support bracket. Then, reassemble the microwave by tightening loose screws and reattaching the control panel.

Other Possible Causes:

While less common, there are other potential causes for a microwave running without heating. These include a blown thermal fuse/thermal protector, defective high voltage capacitor, damaged high voltage transformer, or a malfunctioning control board. If the above solutions don’t resolve the issue, it is best to consult a professional technician.

Final Thoughts

Hopeffully by following these steps you will be able to identify and resolve your microwave not heating issues.

If you are still having problems is probably time to buy a new microwave or get it fixed by a professional technician.