Why LG Microwave Not Heating or Turning?

Microwaves can be frustrating if they don’t heat or the turntable doesn’t turn. It is unusual for both of these things to happen at the same time while the oven still powers on. However, there are ways to diagnose the issue and remedy the problem. 

There are a couple of reasons why your LG microwave isn’t heating or turning. It could be a child lock is activated, a failed diode, or a turntable motor. It could also be the magnetron needs replacing. 

Some of these issues will require a service technician to repair but you can work through the process to figure out if it’s something you can fix or if you need to call the support center. 

Read further to find out how to diagnose the issue and work through the problem. 

Error Codes

Most of the time, LG microwaves will display an error code to let you know there is a problem. These error codes aren’t specific but they do point you in a direction that can help you diagnose the problem. 

Your owner’s manual should have a list of common error codes. The most common error codes are also available for LG online but you may need to do a little research. Be sure to look at error codes for LG and products sold in the United States. 

Manufacturers have different codes and even produce different codes for products sold in Europe. 

Read: How To Vent A Microwave On An Interior Wall

Reset the Microwave

LG, like all microwave manufacturers, recommend you do a hard reset on a non-working oven before delving into the mechanics of it. A reset will clear any errors as well as the control board. Many times, a hard reset will fix the problem.

You can do a hard reset on your LG microwave by unplugging it from the power outlet. Wait three minutes and plug it back in. You will need to reset the day and time using the clock button. You can enter the time, minutes, and morning or night setting by pressing the dial.

Read: Microwave Blown Fuse Symptoms

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Test the Microwave

The next thing you should do is test it to see if the reset worked. Put some water in a microwavable mug or bowl and put it inside the oven. Clear the keypad by pressing clear or reset. 

Cook the water for 60 seconds. Check to see if the water heats. 

The Results

The test should reveal the issue with your microwave. A keypad that doesn’t respond at all and won’t let you cook means the child lock feature could be on. This feature locks the control panel so kids can’t use it without supervision. 

Read: Top Reasons Why Microwave Is Not Heating

Testing the Child Lock Feature

Here is how you get the lock and activate or de-activate the feature. 

Press stop on the keypad. You can activate the lock by pressing the start button for four seconds. An “L” will pop up. You can deactivate the feature by doing the same thing. Only the “L” will disappear from the display after you hold down the start button.

Water Poorly Heating

Water that heats poorly could be the power level is too low or the timer function was mistakingly activated. You could have used the wrong cook settings too. 

No heat, No Turntable

Now, we are getting to bottom of the problem. You have power but no heat. Also, the turntable doesn’t work. These are actually two separate problems with two different solutions. 

A microwave that has power but isn’t heating at all likely has a blown diode. That is the most common reason for this problem. 

The diode is responsible for converting electricity into high voltage energy that powers the magnetron. The magnetron then heats the food. This can up to 5,000 volts. A faulty diode means the magnetron doesn’t get enough voltage to function. 

You can look at the diode to see if it’s burned out. Those who aren’t sure can also test it with a multimeter.  However, most experts recommend that DIYers don’t do anything other than look at the diode because of the massive amount of electricity that runs through the appliance, even if it’s unplugged. 

If you suspect it’s the diode, it’s best to call a professional to replace it. 


The magnetron, the part responsible for cooking your food, could have blown out and that would mean your microwave is not heating. However, that wouldn’t affect the turntable function.

The magnetron is a highly dangerous component and would need professional servicing for testing and replacement.

Read: 5 Possible Issues When Microwave Turntable Is Not Turning

The Turntable

A turntable that quits working is probably because something is wrong with the turntable motor. Use a multimeter to see if there is continuity in the turntable motor. These can be replaced and you may be able to do this project yourself safely with the microwave unplugged. 

Common Problems

A couple of things could cause both the heating and turntable issues. These can include the door switches or a bad control board.

Door Switch

One is faulty door switches. These are three to four switches that relay messages to the control board when the door is open or closed. They issue these relays in sequences to be sure the door is closed. 

A failed door switch will not allow the microwave to start or heat. It could also control a feature like a turntable. You can test each of the switches with the multimeter for continuity to see if they are the problem.

However, like testing the diode, there is a risk involved so make sure you know what you are doing to avoid injury or death. 

The Control Board

The main control board has parts of it that control different features in your microwave. Some of those features may have burned out on the board. You could replace just those features but it really would serve you best to replace the whole board if this is the problem. This is one of those repairs a service technician needs to do. 

Read: 5 Reasons Why Microwave Is Sparking Inside

Why did my microwave suddenly stop working?

A microwave that suddenly stops cooking likely tripped a fuse in the electrical box. Check to see if the switch to that outlet is flipped and turn it back on. 

How long should an LG microwave last?

Most name-grand microwaves will last around seven years under normal use. The best way to get your microwave to last as long as possible is to keep it clean and perform regular maintenance on it. 

How many fuses does an LG microwave have?

There are three fuses in an LG microwave oven. There’s one in the top center, one in the upper right corner, and one in the lower right corner.

Do you have to reset a microwave after a power outage?

Yes, you will need to reset your microwave if the power goes out. It is best to unplug it when the power goes out so an electrical surge won’t damage it when the power comes back on. 

Once it’s unplugged, you will just need to plug it back in and reset the clock once you have power. 

Cost of Fixing and LG Microwave

Microwaves are typically pretty cheap to fix with the average price running between $50 and $100. If you paid more than that for your microwave, it is probably worth fixing. Those buying a cheaper version may want to consider just buying a new one, depending on the age of your oven.

Calling the Support Center

There are some things you need to have on hand when you call the support center about your microwave. You will need the make and model number. You should also have the warranty information available to see if any repairs fall under the warranty.

Your warranty should have an issue date on it showing when it started. Sometimes, having the purchase receipt is also helpful. This is especially true if it’s a new microwave.

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