Microwaves can be a real convenience in the kitchen, and if your microwave suddenly stops heating (or works intermittently), it can be more than a little frustrating. Here are some of the most common issues of Whirlpool microwave not heating and ways that you can troubleshoot them.
Microwave ovens use microwave radiation to heat food. This is a form of non-ionizing radiation. Microwave energy causes polarity in water molecules, causing them to vibrate and generate heat. The heat is then transferred throughout the food. The microwaves can’t be felt or seen by humans.
If your Whirlpool microwave is not heating, this is the ultimate diagnosis guide for you. If you have tried all the simple solutions to no avail but can’t afford an expensive repair, this article will help you to diagnose the problem and fix it yourself. The microwave repair will range from replacing a fuse to replacing a controller board or an entire motor module.
Whirlpool Microwave Not Heating – Troubleshoot and Diagnosis
There are a few potential issues that may have caused your Whirlpool microwave malfunction. The microwave may have been on too long, causing the magnetron to burn out. It’s also possible that a faulty fuse or capacitor may be the cause of your malfunction. However, if these parts were not damaged, then it is possible that a previously undetected problem exists in the circuitry of the microwave. You may not be able to fix it yourself, so call a professional for advice and/or service.
IMPORTANT: It is important to know that even when a microwave is unplugged, it holds a lethal amount of electricity. If you are not an electrician/professional, please leave the repair to them.
When a part of a microwave breaks down or fails, it can leave you scrambling to come up with a fix. But with this simple guide, you won’t struggle anymore. Learn about what goes wrong in microwaves and how you can repair them; troubleshoot your microwave to find the root of the problem, and find the answer to why your microwave stopped heating your food or caused smoke to shoot out of it.
To make sure your microwave is working correctly, start by checking these basic settings:
- Ensure that Timer function is not ON
The microwave is like many other machines that you use in your kitchen. You may mistake the different buttons for different purposes, but if you need to cook your food, you don’t want it to count down; you want it to start cooking immediately. Some microwaves have a timer that counts down the time that has already passed, not the time it takes to cook your food. Most timers start counting when you press “Start” and stop when your food is done. If this happens to you, try pressing “Start” again after the timer has counted down the number of minutes left for cooking, and use an additional feature like “Add 30 Seconds” or “Cancel.
- Ensure that door is properly closed
If your microwave door isn’t shut all the way, it won’t count as a closed door and the microwave won’t work. Make sure the door is shut all the way, but don’t slam it because you’ll break something.
If your Whirlpool microwave is not heating up, then your microwave may be experiencing one of the following issues:
The microwave diode is a specialized diode that has been developed for use in microwave ovens. It works by converting the A/C power output of the transformer to D/C, doubling the voltage and increasing it to nearly 5,000 volts. The high voltage (HV) from this diode powers the magnetron. The magnetron itself generates microwaves from this power, which heat the food.
If the diode burns out, the magnetron won’t receive enough voltage to operate , and as a result, the microwave will fail to heat food as expected.
If you see a burnt looking diode, it means the microwave needs to be fixed. In most cases, this can be resolved by simply replacing the diode. While this may seem like a difficult task, it shouldn’t be too overwhelming for someone who works with electronics. If you have no idea what you’re doing, however, don’t try to fix the microwave! Contact an expert instead.
When your microwave acts up and you think it’s the microwave diode, there are several things you can test to determine whether the diode is faulty. First, inspect the diode visually to see if it’s been damaged—if it looks blackened or burnt, then it’s likely faulty. Next, use a multimeter that uses a 9-volt battery or put a 9-volt battery in series with the diode. if diode fails continuity test, then replace it.
Defective Door Switch
The door switches on most microwaves have three or four different positions, and each position offers a different safety mechanism for the door. When the microwave starts warming food, it completes a circuit between two contacts. When you close the microwave door, it makes contact with the first set of contacts. If everything is working properly, it will continue to complete a circuit to the next pair of contacts, and so on.
If any of the microwave door switches fails, the microwave will not heat. So be sure to troubleshoot your microwave right away if you’re experiencing a problem with it.
Testing the door switches of your microwave is a quick way to identify possible problems with the door. First, check if the door latch is in good working order. If it is, you’ll get an audible click when you try to open or close the door. Next, check the continuity of each of the switches to see if they’re working correctly. A defective switch will produce little to no resistance when you test it with a multimeter. Replace the defective door switches with new ones.
Burnt Out Magnetron
A magnetron is a vacuum tube that uses high frequency alternating current to generate enough energy to create high-power microwave radiation, which can cook food quickly.
The magnetron is the part of the microwave that allows it to make waves that turn your food into your favourite meal. Magnetrons are often burned out by food, water, and steam over time, but may last if you take care of your microwave well. If your microwave is no longer heating food or beverages, the magnetron may be damaged.
The magnetron is not repairable — you have to replace it.
Burnt Out High Voltage Capacitor
In a microwave, the capacitor and the diode function together to convert AC voltage from the transformer into DC voltage. This boosts the surge of power that gets into your food, which in turn allows you to cook dishes faster.
Microwave ovens have a high voltage capacitor, which stores excess electricity and distributes it through the circuit. If the capacitor is burnt out, the entire high voltage circuit will stop working properly, and the microwave won’t heat.
To test the capacitor in your microwave, plug it in using an electrical cord. Place a VOM set to measure capacitance across the two wires that were connected to the capacitor when it was running. The VOM should show a reading above 10 microfarads. If it does not, replace the capacitor with a new one of the same uF rating and try again. Replace the capacitor if you still get no reading.
Failed High Voltage Transformer
Microwave ovens, which use the electromagnetic spectrum to heat food, produce a high voltage in order to power the magnetron antenna. This magnetron antenna is what emits the energy that cooks your food.
When a microwave transformer fails, it may give off sparks, smoke or even an unpleasant burning smell. You should unplug your microwave immediately if you notice any of these signs, as using it can be extremely dangerous.
Blown Thermal Fuse
If microwaves overheat, they can cause a fire. A thermal fuse is a safety device designed to cut off power to a microwave if it overheats. If the microwave is cycling on and off, if it is producing excessive heat, or if you smell something burning, that might be a sign the fuse has been triggered.
If the microwave doesn’t heat up, a fuse may have blown. To check if a fuse has blown, use a multimeter to test for continuity. If the fuse doesn’t have continuity, then it has blown and should be replaced. If the fuse blows, a new one is needed. Do not attempt to reset it.
The thermoprotector protects your microwave by shutting it down if something causes the inside to overheat. Microwave won’t start or heat anymore if thermoprotector trips.
When troubleshooting your thermoprotector, check continuity to ensure it is not the thermoprotector at fault. If there is no continuity, it can be confirmed that the thermoprotector has failed and must be replaced.
Main Control Board
If your microwave doesn’t heat food, the problem might be a bad control board. If you’ve checked all of the other parts and they’re working, replace your control board.
Hi there! I’m Sam Hendricks, and I’m a repair technician and expert. I created this website to help people like you save money and time by fixing your own appliances.
Over the years, I’ve seen people spend a lot of money on unnecessary repairs or replacements. That’s why I decided to share my expertise and create easy-to-follow guides for fixing appliances on your own.