Microwaves make life easier as you get to warm food within a short time without any major challenges. These appliances should be a must-have in the kitchen. But like any other appliance, it comes with its own set of problems. For example, the lights may dim/flicker whenever you turn the microwave on.

As the microwave turns on, it will draw extra energy for a few seconds. However, there are times when it might not work as it should and affect your home’s lights. When lights dim/flicker when the microwave turns on, it could be an issue with the power supply, an overloaded circuit, or a poor wiring connection. 

Read on and find an in-depth explanation of the causes of light flickering when the microwave turns on and possible solutions.

What Causes Microwave Light Flicker/Dim?

  • An Overloaded Circuit
  • Improper Wiring
  • Low Power Supply to Your Home
  • Problem with The Bulbs
  • Microwave Draws High Voltage
  • Faulty Dimmer
  • Microwave and Lights Share Circuit/ Wiring
  • Loose Connections Between the Outlet and Plug

An Overloaded Circuit

One of the reasons lights dim whenever the microwave turns on is an overloaded circuit. This happens if several large appliances share the same circuit interfering with the amount of power reaching the lightbulbs. This could also result if the circuit breaker is spoilt, interfering with the bulbs’ electrical supply, making them dim.

The Fix:

You need to have a circuit just for your microwave to avoid experiencing such a problem. But, if possible, have every appliance in the kitchen on its circuit to prevent overloading the circuit. If you can’t afford to do this, consider using the appliances one at a time. For example, you can disconnect the electric cooker when using the microwave.

Improper Wiring

Another reason the lights would flicker when you turn on the microwave is improper or faulty wiring. Remember, the wires in the house transfer energy to the bulb and the appliances you use at home. When they’re incapable of doing this, there will be less power supply, affecting the amount of current reaching the lights and microwave. So, if you turn on the microwave, it will draw much power leaving less for the lights making the bulbs dim.

The Fix:

You can change this by working on the wiring connection. Replace the loose ones and repair the damaged ends that interrupt the power supply. However, if your home has outdated wiring that can’t meet the microwave’s demands, it’s best to re-do the wiring in the whole house. Work with a licensed electrician to help out as live electricity can be dangerous.

Low Power Supply to Your Home

The high demand for electricity in your neighborhood might affect the power supply in your home. This happens mostly if the power grid has issues. For example, if too many homes rely on the power grid for their power needs, it might overpower the energy generated.

The Fix:

If there’s less power supply in your home and you switch on a powerful appliance like a microwave, the lights will dim. The lightbulbs, in this case, will be struggling with the little current reaching it to light. But you need to remember that a low power supply to your home could be because of power fluctuation on the transformer.

You may have little control over this as neighbors are prone to share a power grid. But you can have a backup power source to meet your house demands.

Problem with The Bulbs

When you turn on the microwave, the lights flickering could also be nothing to do with the appliance but rather the bulbs. It could be that the bulbs are old, having served for long and nearing the end of their lifespan.

When the lightbulbs are old, their filament will be brittle, making them flicker. The bulbs might also dim if they’re loose, interfering with the power reaching them. The solution is replacing the bulbs and having them work as before.

Microwave Draws High Voltage

The modern microwave models require high voltage to start operating. So, if you turn yours on and the lights flicker or dim, it’s because of the high voltage the appliance draws, leaving the lightbulbs with the little current to run.

This should not worry you as the microwave will not draw high energy all through as it operates. Instead, it will use less amount to run after picking up. But if the bulbs continue flickering after this large appliance picks enough power, consider calling a technician. The professional will diagnose your appliance plus the wiring connection to know the root cause of the problem.

Faulty Dimmer

If you install a dimmer switch in your house to help manage your utility bills, then it could be a reason the lights keep flickering. This device controls the amount of energy flowing through the circuit. So, if it’s faulty, it will affect how much energy reaches the lightbulbs and microwave.

Additionally, the dimmer switches work with high voltage LED lights which draw much energy to light. Note that the dimmers also have to be compatible with the bulbs. So, if the lights flicker if you turn on the microwave, LED bulbs are not compatible with the dimmer. If you turn on a microwave when there’s less energy in the circuit, the lights will dim. Determine where the problem is and work on it to resolve the issue.

Microwave and Lights Share Circuit/ Wiring

When you turn on a microwave, the dim light could be because of a shared wiring connection. If the bulbs and the microwave run from the same wiring or circuit, it will be challenging to get enough power to run the two.

But when this happens, the wiring won’t be able to supply enough energy to sustain the current demands of the microwave. If this is an older wiring system, they won’t be able to transport energy that can turn on such a large appliance as a microwave.

Consider fixing newer wiring in your kitchen to enable your microwave to turn on without affecting the lights. If your microwave and bulbs share a circuit or wiring, look for a way to rectify this so that each is independent.

Loose Connections Between the Outlet and Plug

If there’s a loose connection between the plug and the outlet, it will affect the power supply to the bulbs and the microwave. This could be because of a cord that is tripped over when you accidentally remove it from the main outlet.

Your microwave will, in this case, not get enough energy supply. As you know, a microwave is a large appliance which draws much power as it turns on. So, as it uses the little power available, it will affect the amount of energy reaching the lightbulbs, making them dim.

Furthermore, this issue could arise from a damaged cord. This will make the wires not supply the required voltage to run the microwave and bulb concurrently. So, the lights will dim if you turn on the microwave.

The Fix:

You need to work on the loose connection between the plug and the outlet to avoid experiencing such a problem. But replacing the wires in the cord to have a sufficient power supply will also do you great.

Bottom Line

Your lights dimming as you use the microwave can be a danger sign if it lasts longer than a minute. Remember, the microwave will draw much power as it turns on as it’s a large appliance with high voltage consumption. However, if this lasts longer, you need to find the cause and diagnose it before experiencing many problems later.

It could be that your home has less power supply or the circuit is overloaded. Sometimes this could be a wiring problem or an issue with the bulbs. Look for the best way to solve any of these and have your appliance working without major challenges.