Strange goings on...

[JohnW2]

Intriguing. I know it's a silly question, but I take it that you're absolutely certain that the behaviour you're now seeing was not present before the bulb blew?

Hi John. 100%. As far as I was aware they were entirely separate, as there are no mutual switches...clearly that can't be the case.

I assumed so. In that case, regardless of how/why the situation has arisen, something is very wrong, and possibly even potentially dangerous. I therefore don't think you have any choice but to get an electrician in to tackle the puzzle, and I'm sure that many of us here would be grateful if you could eventually tell us what the explanation was!

Kind Regards, John

 

[rekrabwuh]

unscrew each ceiling rose and genitally touch each wire looking for a lose one.

That sounds painful...

I'm not entirely sure I'm cut out for this, particularly when electricity is involved, so might be best to get someone in...

 

[JBR]

"rekrabwuh" may be able to unscrew each ceiling rose and genitally touch each wire looking for a lose one.

I fell about laughing at this. Of course, I know you meant 'gently', but the other option sounds so much more fun!

 

[TheKeymeister]

Definitely sounds like an inadvertent back feed on the lighting circuit, possibly caused when changing the switches if it's never happened before. There's probably a fuse blown for the downstairs lighting circuit but you need to find out where the back feed is coming from to make the installation safe really.

"rekrabwuh" may be able to unscrew each ceiling rose and genitally touch each wire looking for a lose one.

I fell about laughing at this. Of course, I know you meant 'gently', but the other option sounds so much more fun!

It all sounds like a bit of a cock up to be honest