Multi-Band RFI From Induction Cooker?

In my younger days as Amateur Radio operator, only interference at home was what we often called as “Mixy QRM” when mother started the Mixer/Grinder in the kitchen and we had to stop our radio communication due to the loud noise. Many of us used to pause during our ragchews on 40 m citing Mixy QRM. But that was just a noise QRM and not a radio frequency interference in our radios. Now things have changed drastically. Many of the devices at home produce radiofrequency interference in our radios starting from LED lighting in the room. Today I noticed multi-band RF interference from an induction cooker which I had switched on to boil drinking water!

Usually it is not switched on during my radio operation times and vice versa. Today morning I had finished elevating my fan dipole antenna about 1 m more and wanted to check it out. As there was a scheduled maintenance for the electrical grid power supply, I had to wait till noon for the power to be restored. For the same reason, I wanted to boil drinking water as well. So I switched on the induction cooker first and then came to the radio. To my surprise I found extensive noise on 7, 14 and 21 MHz, the bands which my fan dipole caters to.

Recorded short video clips from each band and then moved to 50 MHz, just to check. Of course, my antenna was not meant for 50 MHz and I found the band to be quite silent.

I had to wait till the water boiled, to check again by switching off the induction cooker. As expected, it seems to be the culprit.

The RFI in the waterfall display disappeared on switching of the induction cooker, only to reappear when it was switched on again.

It is possibly because the powerline to the induction cooker is routed through the wall of my shack. Now I have to schedule my amateur radio operations so as to not clash with the work of the induction cooker or use only LPG for cooking at home when I am on the band! I will also have to check the availability of ferrite beads in the local market to see if slipping some of them on to the power cord of the induction cooker will be of any use.