These days a microwave oven in the kitchen is a staple of nearly every home. Rarely do you find someone without one. Depending on the size and quality of the unit—a microwave can function for several years before you need to replace it.
A common problem in many models is that the microwave turns on by itself. Some models, even after they are unplugged, will even store enough power to turn on by themselves.
Anytime a microwave begins to operate without being turned on, it becomes a fire hazard.
When this happens, the oven needs immediate repair or replacement. If neither is possible—then the microwave needs to be unplugged and its door kept open when not in use. If the faulty oven is used, close supervision is recommended in case of fire. Here are five reasons why a microwave might turn on by itself.
Faulty Board and Switches
In the past, customers reported their microwaves from a particular manufacturer turning on by themselves. Even when the customers hit “cancel” on the microwave—it would come back on. This issue was not a small one.
It was discovered after research that a faulty board or switch on the microwave could lead to such an issue. In such a case as this, contact the manufacturing company and ask them to replace the board or switch.
If the microwave light and motor turns on, but there is no heat, and the turntable does not spin—it could be that the interlock switch in the door is stuck. It might also be that the interlock relay on the control panel is stuck.
Heat Sensor Panel
Many times microwave buttons are heat sensitive. You do not really have to press any buttons, but the warmth of your finger will be enough to press the buttons.
If this is how your microwave works and it is an over-the-stove model, it may be that the heat from your oven or steam from a pan on the stove is tricking the sensor panel into thinking that someone is touching the buttons.
If the microwave turns itself on and unplugging and resetting it does not resolve the issue, then the problem might be in the control panel.
The touch pad could be defective, or something has gone wrong in the control board. If the control panel is supplying voltage to the cooking components when it has not been told to do so by the user, then something is likely wrong with the control panel.
The membrane keypad, although not available as a separate part, can be replaced. This is a relatively easy do-it-yourself kind of a job. Since it’s not sold separately, you will have to order the control panel frame assembly, which will come complete with a new membrane keypad installed.
You will need to remove the existing control panel frame assembly from your microwave. With that done, you should be able to replace it fairly easily.