Microwave not heating: troubleshooting help and solutions
Microwaves deliver the convenience that every home cook and family needs. However, a microwave that won’t heat as intended can disrupt your routine, making meal prep and cooking more challenging.
This guide provides six common reasons why your microwave may not be heating, including when it appears to be working yet not heating the contents effectively.
What would prevent my microwave from heating?
Typically, broken parts or misset functions are common reasons why your microwave is not heating up as it should. Settings like Demo Mode, Control Lock Mode, or power levels set too low could prevent food from cooking. Another cause can be a broken part, such as the magnetron, door switch or high-voltage diode.
Possible causes and fixes of a microwave not heating
Diagnosing a malfunctioning microwave may call for a range of solutions, from simple fixes to complicated repairs or part replacements.
The list below covers six possible causes of a microwave not heating and possible solutions for each.
1. Disconnected from the power source
The first step is to inspect if your microwave appears to be off. If so, it may be disconnected from the power source, and you simply need to plug it in.
If it’s connected to the power, you should still unplug the appliance from the outlet (if applicable) and then plug it back in. Another option is to check the breaker box to see if the circuit for the microwave has tripped.
2. Is Control Lock or Demo Mode enabled?
The Control Lock function found on many models stops the microwave from operating to prevent accidentally starting a cycle while cleaning the control panel.
Your microwave may have an indicator on its control panel to display when the control lock is enabled. Whirlpool® Microwaves, for instance, often show a “LOC” or “L” code on the control panel to indicate that the Control Lock has been activated.
Demo Mode makes models appear to be functioning but will not heat food. In this mode, the light and fan will usually switch on, and the turntable will rotate, but the magnetron responsible for heating food will not work.
Refer to your appliance’s owner’s manual to review which of your microwave’s functions could potentially interfere with its heating ability. Your owner’s manual is also where you can learn more about error codes or light indicators that may be displayed.
3. Delay Start is on
Select models have a Delay Start function. This feature is for setting the cook time and power level, among other settings, and then a timer for when the cooking cycle should activate.
If you notice that your microwave has not begun a cycle by pressing the “Start” button, you should see if the “Delay Start’ function was activated. If so, turn it off and then select your settings and press start to see if the cooking cycle begins.
4. Set to low power level
Most microwaves feature five to 10 power settings. These settings offer a range of cooking abilities, from warming vegetables to quickly heating soups. However, a microwave may heat slower than usual if the power level is set too low for a certain type of food. Double-check your microwave’s power level to ensure it’s the correct percentage of power based on what you’re trying to heat.
See this guide to microwave power levels for more information on which power levels to use for different types of food.
5. Broken microwave parts
If you’ve ruled out the more common solutions, then there could be a more complex reason why your microwave is not heating.
Other potential causes may include:
- A broken high-voltage diode
- A defective magnetron
- Other broken or malfunctioning internal parts
For more complicated issues, schedule an appointment with a professional to diagnose what’s wrong and perform the necessary repairs.
6. Faulty door switch
A microwave door switch prevents the appliance from starting while the door is open. A broken door switch could also make the door appear to be closed when it is not, preventing the start of a cooking cycle. Additionally, the interior light may remain on with the door closed or not turn on when the door is open.
Installing a new door switch can be a lengthy process involving disassembling the control panel and wiring. This is typically a job for a professional. Always consult your owner’s manual before making any repairs.
Whirlpool® Flush Built-In Design
A streamlined style to elevate any kitchen
Whirlpool® Microwaves with Flush Built-In Design* elevate your kitchen with a microwave that complements and fits in with your cabinetry and aesthetic.
*When installed in standard cabinet depth 12-3/4-in.
Need help with your Whirlpool® Microwave
If you’re experiencing issues operating or troubleshooting your Whirlpool® Microwave, the Whirlpool Customer Care Centre can help. Get answers to your questions, find replacement parts or schedule a service to help repair your microwave to get it operating as it should.
Explore Whirlpool® Microwaves
If you’re looking to upgrade, shop microwaves with the features and finish that can complement or even elevate your kitchen. Select Whirlpool® Microwaves come with impressive features like Sensor Cooking, which automatically adjusts cooking times as necessary. Select models go beyond heating foods with features like Grill Mode, Air Fry Mode and Steam Cooking to help sear, crisp and steam your favourite foods like french fries, vegetables and more.
Learn more about microwaves with Whirlpool brand
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