Skip to content

06.06.2019

Do Microwaves Block Wifi?

Imagine the following scenario, you are in a rush in the morning and you need a quick breakfast. You empty some porridge oats into a bowl, put it in the microwave for two minutes and let it heat up.

Naturally, you take out your phone while waiting and try to investigate the latest news headlines.

You witness an endless loading spinner that indicates that your Wifi isn't properly working. While trying to work out the issue the microwave beeps and the porridge is ready.

All of the sudden your phone starts to work again. Surely the two aren't related? Well, thats what I thought until I did a bit of research and found quite a lot of people are asking this question.

So, do microwaves block Wifi?

Microwaves can indeed block Wifi as both microwaves ovens and Wi-Fi operate on the same frequency (2.4 GHz) .

With both operating on this same frequency, a properly installed microwave door should in theory block the radiation from the magnetron (vacuum tube that powers the microwave) from escaping but as this is not 100% reliable and as a result there are inevitable radiation leaks.

For no leakage to occur, the microwave would have to have a good seal, properly design cavity and no damage to manufacturing defects.

Only the tiniest amount of leakage is required to cause an interference. From my research, this leakage is considered not dangerous to humans, but can really affect web access.

The amount of radiation leaked can vary and will depend on the build of the microwave. This results in electromagnetic or radio-frequency (RF) interference.

Typically a microwave heats up food with about 1,000 watts of power. Thats almost 10,000 times more than a WiFi access point.

Interference like this is not limited to microwaves, it is quite common among 802.11b and 802.11g wireless devices.

This includes:

  • baby monitors
  • cordless telephones
  • toaster ovens
  • electric blankets
  • ultrasonic pest control devices
  • bug zappers
  • heating pads

I found a great demonstration of a microwave leaking in the 2.4GHz frequency

Thats a quick overview of why this interference occurs, however, I wanted to examine this a little further to get a little more in-depth on the topic.

How do I reduce WiFi interference?

So, if this is a regular annoyance you might be looking to reduce these two frequencies interfering with each other. While this has only happened to me a handful of times I wanted to research to see how the interference can be avoided.

As well are your microwave, wireless interference normally comes from two other sources: walls blocking wireless signals and other Wi-Fi networks using the same channel as your own Wi-Fi network.

If you have come across different variants of internet speed you might be familiar with the 5.0GHz band for WiFi connections.

Older WiFi routers operate within the 2.4GHz which is the same level as the microwave oven. If unsure about what type of WiFi your current setups has, I would check your current router or modem and see if it offers.

Upgrading to a 5.0GHz (dual band) WiFi router will solves this issue completely, as the two devices will no longer be on the same frequency.

It should also be noted that the 5GHz band allows for smaller range than 2.4GHz and reduces the ability to pass through walls.

A more detailed overview of how 5GHz differ from 2.4GH can be found below:

For those that are unable to upgrade their WiFi to 5.0GHZ, distancing your router from your microwave has also been shown to be an effective way of stop the interruptions.

Another slightly obvious remedy is to move the router closer to where your Wi-Fi devices are being used. While this can't guarantee that your microwave won't interrupt, it will certainly increase the chances of your Wi-Fi devices staying consistently connected.

If you are still having trouble with interruptions, it might worth taking a look at the microwave itself.

If it's consistently having a profound effect on your devices ability to connect its worth thinking about replacing the microwave. It's shield (door) must be leaking to some extent. And while you could consider repairing it, there is no guarantee that it will still not leak

Throughout my findings, a test for a microwaves shield kept rearing it head.

The test has you putting your mobile phone inside the microwave (without turning it on!) and then trying to ring it to see if it still receives a signal.

If the phone receives a signal, the microwaves door casing is said to be leaking radiation.

I can't say I condone or even know enough about the safety of tests like these but I'll let you decide for yourself with this video that I found:

I think fixing the shielding yourself is normally difficult to impossible to get right. You can test it by putting a 2.4GHz cordless landline phone inside, and see if it communicates with its base station. (But don't turn the microwave on, you'll fry the phone). If the shielding is working, the phone will not communicate with its base station.

Why do Microwaves use 2.4 GHz?

After examining some reduction measures, I wanted to know more about these frequencies, specifically 2.4GHz.

So if other devices transmit frequencies on 2.4GHz, why would a microwave or Wifi for that matter choose to be on the same bandwidth?

I wanted to find out more.

Interestingly, I found out that microwaves, WiFI networks and other devices could easily be made to resonate at other frequencies but instead they are emitting at a frequency that is not supposed to be used for communication.

The frequencies in this range seem to be the place where devices broadcast to when they aren't provide a useful action of communication (heating for microwaves).

These broadcast actions could be classified as miscellanies. Frequencies around 2.4GHz are called an ISM band. Slowly over time, these frequencies were utilised for less important frequency transmitters.

So, if this space acts as something that dumps less useful broadcasts, why are most of them forced to do so?

Well, they are forced into this 'waste' frequency because there are government enforced regulations about what frequencies can be used for what purpose.

The reason 2.45 GHz is used is because it is in the centre of the unlicensed ISM band of the FCC. This is the main frequency band of the Industrial, Scientific and Medical (ISM). This band is primarily reserved for non telecommunications applications.

There is loose regulations around it and as a result it does not require an FCC certification of compliance.

2.4GHz has been deemed acceptable to broadcast on without any license. Thats right, there are licenses for frequencies that are invisible to the naked eye!

2.4GHz is allowed to be used with any consumer equipment. This is due to the fact that 2.4GHz isn't able to travel far and because of this the likelihood of it interfering with anyone more than 100m away is very slim.

Unless you are in the locality of an important frequency ( hospital or aviation equipment) there isn't much of a chance of disrupting anything important.

The fact that all these regulations exist on invisible bandwidth and frequencies is something I had never considered as possibility.

If most electronic devices have the potential to emit to a frequency that could cause interruption to important equipment. then I can understand the regulations that exist here.

Conclusion

The interference that I experienced with my WiFi sent be down this rabbit hole of research. And while I can't fully comprehend some of the more in-depth info about electrical engineering and frequency channels. I still really enjoyed learning about these different aspects.

The fact that a special type of frequency wasteland exists where appliances and electronics have free reign to carry out their functions is truly fascinating.

I'm sure there are plenty more scenarios where some home appliances overlap with each other in terms of functionality.

If you have experienced a similar situations, I hope this article helped you.

Recent posts

  • Top 15 Home Appliances That Use The Most Electricity
  • 20 Thoughtful Appliances for Wedding Gifts in 2020