How to Fix LG Microwave Not Heating

Imagine a situation where you are to resume work early in the morning then you decide to heat your food and your microwave oven stops heating without any idea on what to do. You are so going to be pissed off that it might ruin your day because you won’t eventually eat to work that day or perhaps depend on gas to heat up the food. It will be more disappointing if you’d need to defrost it before heating it.

Generally, LG products are considered to be one of the best products, their durability and longevity put them ahead of many other manufacturers. However, LG microwave not heating issues are often caused by inadequate or spike in power supply and inputting a wrong setting.

Here in this article, we would briefly discuss the issues of your LG microwave not heating and how to solve this problem.

How to Fix LG Microwave Not Heating

LG microwave not heating issue may be caused by entering the wrong settings or from an inadequate power supply.  Normally the microwave often displays an error code,  when there is a severe problem that requires to be fixed by a technician. The error code would give you a signal on what is the actual problem. But there are certain situations when there will be no error code on your microwave display screen.

Reset Your LG Microwave

In such a situation we would show you various troubleshooting steps that would help you to fix such issues.

LG Microwave Reset

  • Place a microwaveable safe cup, mug, or bowl of water inside the unit.
  • Press clear/off or reset to clear the keypad.
  • Press cook and enter 60 seconds
  • Check the water to see if it was heated.

Power Cycle Your LG Microwave

In a situation where there is a power surge in the electric power supply, you may be forced to power cycle your LG microwave. This allows your microwave to cool off and reset power from within.

  • Unplug your microwave from a power outlet or switch off the circuit breaker to cut the power supply to the microwave.
  • Allow your LG microwave to remain unplugged for 10-15 seconds.
  • Restore power to your LG Microsoft.

LG Microwave Defective Door

Defective Door

If there is something that is preventing the door of your microwave from closing properly this can lead to the issue of your LG microwave not to heat up.

Most microwaves have between 3 to 4 door switches. When the microwave door closes, the door switches are activated in series so that the door is properly closed. When any of the door switches fails, the microwave will stop heating.

To fix this issue check if something is preventing the door from closing properly, if any it has to be removed or you can also rearrange the inner compartment of your microwave to ensure the door is properly aligned.

Also, check if any of the door switches is defective, you have to ensure your microwave is properly plugged into a power outlet. Then use a multimeter testing tool to test each of them for current. If any of the door switches fails to read, then it is faulty.

Faulty Thermistor

A Thermistor is a thermally sensitive resistor that increases or decreases changes in electrical resistance in response to changes in the temperature of an appliance. The thermistor measures and controls the measurement of temperature in an appliance including your LG microwave.

Ensure you unplug your LG microwave from a power outlet, also ensure that the wires are removed from the thermistor. Then use a multimeter or ohms meter to check for current in the thermistor. Connect your ohms meter or multimeter with the wires connected to the thermistor.

Tripped Thermal Fuse

The thermal fuse trips off the current flowing to your microwave when there is a power surge. The device trips off to protect your microwave from potential damages due to the spike in electric current. Use a multimeter to test the thermal fuse. If the fuse fails to read, then it needs to be replaced. Note that the thermal fuse can’t be reset nor fixed it must be replaced.

Humidity Sensor Error

The humidity sensor senses the humidity and is installed close to the air outlet. The air inside the cooking cavity is heated when your microwave oven performs its cooking functions. The heated air is then discharged to the exterior atmosphere through the air outlet. The hot air overheats the humidity sensor and this reduces the sensing performance of the sensor.

Also moisture and contaminants like oil and smoke which are created during a cooking cycle settle on the surface of the humidity sensor. These deposits can be hard to remove from the sensor which in turn reduces the sensing performance of the sensor.

Damper Switch 

The damper switch uses an alloy spring for opening and closing the vent damper of a microwave oven. The vent damper switch controls the flow of air through an inlet port into the chamber. Air is blown by the blower motor through the punctured holes on the side panels of the heating chamber. The air that is drawn internally thus cools the magnetron and other parts before moving into the heating chamber. The damper motor controls the damper switch so that it opens and closes the blower inlet.

If the damper motor or switch is defective this can lead to the issues of your LG microwave, not heating. Since there won’t be enough flow of air to heat the oven.

LG Microwave Not Heating

New LG Microwave Not Heating

In case you recently purchased a new LG microwave and you are experiencing heating issues with it, then you should check the connection of your power supply.

Follow these steps to solve this issue:

Check circuit Breaker 

The circuit breaker is connected through the power supply in the main building. The circuit breaker automatically trips off when there is a surge in the power supply.

The tripped breaker would be slightly out of line with the other breakers. Flip the tripped breaker back to the ON position.

If the circuit breaker continues to trip off there may be an issue with the wiring connection in the building and you should call an electrician to check the wire connection.

Check Power Outlet

Ensure you are connecting your microwave to a good power wall outlet. If the wall power outlet is faulty it should be replaced.

Check Power cord

Ensure the power cord of your microwave is firmly plugged into the power outlet. Also visually check if the plug is visually burned and if your type of plug uses a fuse in the power cord ensure you check the fuse is not burned during the power surge.

If you notice that your LG microwave is not heating and you found the power cord to be faulty, ensure you replace the faulty power cord.

LG Microwave Diode

The microwave’s diode converts the AC power of the transformer to a  DC. This doubles the voltage power of the magnetron that heats your food. The magnetron would fail to receive enough voltage without the diode.

A faulty diode would prevent the microwave from heating. Check the diode  for continuity with a multimeter., If the multimeter fails to read then the diode is burned out and should be replaced.

LG microwave

LG Microwave Not Heating And Making Clicking Noise

If your LG microwave is not heating but it makes a clicking sound it can be due to a faulty magnetron, therefore replace a burned magnetron. If replacing the magnetron does not fix this issue, then the issue is from the capacitor. Ensure you replace a defective capacitor, however, if this doesn’t fix the issue, replace the diode of your LG microwave.

LG Microwave Not Heating Food But Runs

If your microwave has power but does not heat food, check the door switch as the door must be properly aligned. Reset your LG microwave, test the thermistor of your microwave, test the humidity sensor, and lastly check the damper switch.

In conclusion, If you recently purchased your LG microwave you can request a warranty. In a situation where your LG microwave is not new then you can request service. You will need to provide your LG Microwave model number and proof of purchase, so ensure you have both readily available.

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