What is this?

[help needed!]

My bathroom extractor fan has not been working and I took the cover off to look, put the cover back on and knocked something and the fan started working.

Stupidly, I took the cover back off to check and now it has stopped working again ‍

I THINK this is what I knocked (See thing circled in red) What is this thing and would it make sense that that is the issue?

(Yes I'm female and have no clue what I'm doing!)

 

[Sureitsoff?]

humidity sensor?

 

[JohnW2]

humidity sensor?

For what it's worth, that was also my first guess, but it's only a guess!

 

[Murdochcat]

Yes that’s a humidity sensor. So that unit should be triggered by turning on the light OR if the humidity sensor.

Was the light on when you were doing this investigation?

Humidity fans are generally tricky to set up.

 

[Harry Bloomfield]

For what it's worth, that was also my first guess, but it's only a guess!

Correct, humidity sensor.

It can be turning on the light, triggered, or by humidity triggered, and once triggered should continue to run for several minutes after the light is turned off. Did you turn the light on?

 

[help needed!]

The fan hasn't been working for a while.

Used to come on when the light was switched on....Now when you switch the light on, the blue light comes but the fan doesn't work.

Until today when t suddenly it started working. So that humidity sensor wouldn't be the reason it started working again if I knocked it?

 

[Harry Bloomfield]

Until today when t suddenly it started working. So that humidity sensor wouldn't be the reason it started working again if I knocked it?

It shouldn't be the reason, no! I would make a guess, at a loose connection to the pcb.

 

[333rocky333]

Whats that bottom right corner, is it a cut off pullcord you might have pulled accidentally and turned it off

 

[andy_nufc]

I think 333rocky333 is in to something there.

This code number is one digit out from that in the photo: (C instead of B) but,

Pics on ebay suggest the 427479B has the pullcord in the bottom right corner, so it seems consistent with the photo above.

 

[Harry Bloomfield]

I think 333rocky333 is in to something there.

OP - Could you give that pull cord a tug, and report back?