While I'm never one to defend Bose, given its recent (well...2 years) spate of awful software releases, this isn't actually a Bose problem. Microwaves emit a signal on the same frequency as wifi. Although microwaves are shielded to some degree, there will always be some leakage, causing wifi to drop for objects near it.
The only way around this would be to use 5ghz wifi signal (which is a wifi standard and many routers support this)...except only the most recent Bose speakers support this (despite it being a standard for a decade). Oh wait, so it *is* Bose's fault. I'll correct myself.
Anyway, if you have the more recent speakers, try switching to 5ghz.
Feb 15, 2017
If your router is only 2 years old it should have 5ghz, usually most modern routers will emit two wireless signals 2.4ghz and 5ghz.
The Soundtouch systems will connect to both 2.4 ghz and 5 ghz networks.
Whilst it is not a Bose specific problem, the Soundtouch range do seem very succeptable to interfearence (poor antennas?).
5 ghz has less range but is a less crouded spectrum, 2.4 ghz has better range but can get messed up by lots of things (bluetooth, microwaves, cordless phones etc).
If you have a 5 ghz WIFI network, get the IP address of your speaker (Settings -> About -> Speakers -> chosen speaker), fire that ip address into your web browser and you should be able to tell it to connect to a different network.
According to this post the new SoundTouch 10,20 and 30 series III support both 2.4 and 5Ghz. I know my original SoundTouch does not. What router do you have?
You are correct, all of our series III systems do support the 5ghz band. This is also true of the SoundTouch 300, SA-5 Amplifier, and Lifestyle 600 and 650 home theater systems.