Bathroom extractor fire & sparks

Discussion in 'Electrics UK' started by Dylan T, 13 Jun 2021.

  1. Dylan T

    Dylan T

    11 Feb 2017
    Thanks Received:
    United Kingdom
    Hi all -

    Have a downstairs shower room that I haven't used the shower in a while as I've had a building project going on - have used the loo as normal but not the shower. It has an extractor fan that comes on with the light. Yesterday had a shower for first time in ages (not an electric one) and about 5 mins in there was a loud bang and smoke, with the board tripping. You could tell it was the fan as was smelling bad. Turned the light pull coard off and the board back on and the fan came back on as normal - but as soon as I turned the light back on there was a huge flash inside the fan (exactly where the terminal block is) and the board went again. I've taken the fan apart and can see what looks like burning in the middle terminal (which is the common live from the switch) and possible the transistor shown, but that could just from the initial soldering i'm thinking. So I'm wondering if anyone could point me to what caused this- can just replace fan but want to make sure it doesn't happen again as was a hefty out blow out. My first guess was some sort of arcing going on that caused a problem with the steam. But i checked the wiring and it seemed pretty decent, so maybe something internal? My other question is why the fan was running fine until the light goes on - i thought maybe the common is keeping the fan on so the timing mechanism which is likely mechanical is kicking back in, but it seems to common live which is burnt rather than the switched live so maybe that kills off that theory. Thoughts greatly appreciated, photo attached. Thanks!

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  3. Taylortwocities


    28 Jul 2006
    Thanks Received:
    United Kingdom
    Yes, new fan needed
    The timing mechanism is electric, not mechanical.
    Your building work may have covered the timer board with clag, or the fan was jammed. Check everything is cleaned out before you switch on the new one!
  4. DIYnot Local

    DIYnot Local

    3 Sep 2019
    United Kingdom

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