Skip to main content

Why Does Running My Microwave Kill My Wi-Fi Connectivity?

There are a variety of household devices and electronics that can interfere with your Wi-Fi signal, but most don’t have the ability to do so quite so spectacularly as a microwave oven. Read on as we explore how a microwave can wreak havoc on your wireless network.

The Question

SuperUser reader Ohlin wants to know why his microwave is slaying his Wi-Fi connectivity:
Every time I start the microwave in the kitchen, our home Wi-Fi stops working and all devices lose connection with our router! The kitchen and the Wi-Fi router are in opposite ends of the apartment but devices are being used a little here and there. We’ve been annoyed by the instability of the Wi-Fi for some time and it wasn’t until recently we realized it was correlated to microwave usage.
After some testing with having the microwave on and off we could narrow down the problem to only occurring when the router is in b/g/n mode and uses a set channel. If I change to b/g mode or set channel to auto then there is no problem any more…but still!
The router is a Zyxel P-661HNU (“802.11n Wireless ADSL2+ 4-port Security Gateway” with latest firmware) and the microwave is made by Neff with an effect of 1000W (if this information might be useful to anyone). There is an “internet connection” light on the router and it doesn’t go out when the interruption occurs so I think this is only an internal Wi-Fi issue.
Now to my questions:
  • What parts of the Wi-Fi can possibly be affected by the microwave usage? Frequency? Disturbances in the electrical system?
  • How can setting Auto on channels make a difference? I thought the different channels were just some kind of separation system within the same frequency spectrum?
  • Could this be a sign that the microwave is malfunctioning and slowly roasting us all at home? Is there any need to be worried?
Since we were able to find router settings that cooperate well with our microwave’s demand for attention, this question is mainly out of curiosity. But as most people out there…I just can’t help the fact that I need to know how it’s possible :-)

Typically it’s the Wi-Fi router causing trouble for other electronics (e.g. the Wi-Fi interferes with the baby monitor) and not, usually, the other way around. What’s going on here?

The Answer

SuperUser contributor Bob offers some insight into why the microwave is causing such problems:

802.11 (b/g/n) typically operates on the 2.4 GHz band. This is conveniently the same/very close to the band that your microwave oven emits. It’s also an ISM band, which can be freely used at low power without licence – it was originally supposed to be used for non-communication purposes, but the lack of a licence requirement makes it very attractive.
Most microwave ovens tend to be very well shielded and will not emit enough radiation[*] to interfere with wireless communications. It is possible that your unit has a damaged shield. You could look into replacing it.
A better thing to do would be to upgrade your wireless networking equipment and devices (note that many, especially older, devices are 2.4 GHz only) to be 5 GHz compatible (used with 802.11 a/n). This is the other major band WiFi networks can operate in (though 2.4 is far more common), and should not suffer interference from microwave ovens.
Addressing your [question about] different channels, microwave ovens (which should label the output frequency somewhere) should use ~2.450 GHz.
WiFi (b/g/n) channels typically range from 2.412 GHz to 2.472 GHz, with a bandwidth of 20 MHz and a 2 MHz band gap. If you pick a channel from the upper or lower end, and assuming your microwave oven is precise enough with its frequency, you could sidestep it entirely. This is, however, just a guess.

[*] I must point out that 2.4 GHz is far from ionising radiation, which is at least 2400000 GHz (the type that can harm human tissue and/or cause cancer). Even if the shield is faulty, it will not cause any harm. Any (very slight) damage would be caused by heating (and not directly by ‘radiation’), which you most definitely will feel before any real damage. Also, just don’t stand in front of it for hours a day. That always helps.



Popular posts from this blog

Advantages and Disadvantages of Wireless CCTV Camera

Advantages and Disadvantages of Wireless CCTV Camera
Before choosing what CCTV Camera system to get, sometimes the customers stumble upon the following question: should I choose wired or wireless CCTV camera? What are the pros and cons of wired and wireless CCTV cameras? As you might have guessed, none of the options available are perfect, so it mostly comes down to your personal preferences. But to make your buying decision easier, Have composea comprehensive list of what you can expect from each type of device, both positives, and negatives. Note that a wireless CCTV camera has to be a digital IP Camera, as only digital signal can be transmitted wireless.
Advantages of Wireless CCTV Camera.
1. Easier installation Wireless IP Camera. This is especially important if you want to do it yourself. That way, you will save time and also ensure that you’re going to be capable of doing it in the first place. In a typical scenario, all you have to worry about in terms of installation is having a powe…

How to Format a Large Hard Drive With FAT or FAT32

32 GB is the file size limit for partitions when formatting with the FAT or FAT32 file system on Windows.What A File System Is & How You Can Find Out What Runs On Your DrivesWhat A File System Is & How You Can Find Out What Runs On Your DrivesREAD MORE Well, as some of you will know, FAT/FAT32 can actually handle up to 16 TB hard drives and up to 2 TB are supported in most operating systems. Microsoft has set a 32 GB partition size limit for the FAT/FAT32 file system to promote NTFS, which is generally more efficient when working with large partitions. In truth, this limitation only exists in recent versions of Windows. Moreover, Windows does recognize large hard drives formatted with FAT/FAT32. Finally, you can circumvent the 32 GB limit. In this article, I will show you how to format a large hard drive with FAT/FAT32 or create a 32+ GB partition with that file system. The Manual Way You don’t need a tool to circumvent the 32 GB partition limit, you can manually format your …

How to Remove Windows Genuine Advantage Notifications

Windows Genuine Advantage (WGA) notifications occur when your computer hasn't passed the validation test. The validation test can be failed due to being sold a pirated (non-genuine) copy of XP, or because you have changed your XP product key to a software-generated key, or sometimes it just happens for no reason at all. The failed validation installs three types of notifications on your computer: one on the log in screen, one log in timer, and one balloon. It also stops updates from Microsoft and disables your ability to install IE7 and Windows Media Player 11. This solution can get rid of all three notifications, even though you will still not be able to update through Windows Update. You will not be able to download things from Microsoft that requires a valid license either. EditSteps
Delete Method 1 If you have only just installed Windows Genuine Advantage notifications, simply using the system restore function will remove the program. Then refuse to accept the WGA update next tim…