Vaillant query?

I have a Vaillant boiler and this morning I noticed a flash of blue light coming from the bottom of it. I've had it for about 7 years or so and never seen this before. My kitchen light was on as well. Last night there was a strange smell in the kitchen, like someone had lit up a match. Couldn't place it and wonder now if it was something to do with the boiler maybe?

I've searched the internet but can't seem to find anyone with this problem - or is it a problem? Maybe this light flashes every now and then and I've never seen it before?

Can someone advise please whether this is normal?

Thank you.

Janet