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Timed extractor fan advice needed

Discussion in 'Electrics UK' started by YouTarzanMeJane, 1 Aug 2020.

  1. YouTarzanMeJane

    YouTarzanMeJane

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    We recently had an extension built but unfortunately the builders were a nightmare when it came to finishing and were doing such a shoddy job in the end we told them to leave and have been clearing up the chaos since.
    The latest discovery is that they installed a timed extractor fan in the toilet (which is what we asked for) but they wired it only to the light with no permanent live to keep it running after the light is off. Is there such thing as an extractor fan unit with a battery for the timer function?? Getting them back to fix it is just not an option so I’m thinking it’s that or putting up with it, unless anyone has any other suggestions???

    Thanks

    (Sorry if this is in the wrong thread. I wasn’t sure which board it fitted in best!)
     
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  3. rsgaz

    rsgaz

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    Do you know what type of cable supplies the extractor?

    i.e. does it have three cores and an earth wire?
     
  4. JohnD

    JohnD

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    no, but is there any access to the light fitting from above, e.g. in a loft or by lifting a floorboard?
     
  5. YouTarzanMeJane

    YouTarzanMeJane

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    No. It only has a blue, a brown, and an earth.
     
  6. flameport

    flameport

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    No, but there are fans which can be powered permanently and have a presence detector in the fan itself.
    https://www.vent-axia.com/product/silhouette-100tm-pir-timer

    Same cable can be used, just needs to have a minor alteration at the point it's connected to the rest of the circuit.
     
  7. YouTarzanMeJane

    YouTarzanMeJane

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    The light fitting only has brown, blue and earth too. There is no access to above it as it is a groundfloor extension with a flat roof (it replaced an old outhouse). 5EA506C2-B435-44F1-975D-BB5359C6DFE4.jpeg
     
  8. flameport

    flameport

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    Please add a photo of the wiring behind the light switch.
     
  9. YouTarzanMeJane

    YouTarzanMeJane

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    Thanks. In case the photo isn’t clear there are 3 cables coming out of the wall each with a blue, brown and earth. The 3 blue wires and 3 brown wires are all going to terminal blocks. 1 brown wire goes into one side of the switch, the other 2 go into the other side of the switch. 88950998-B736-49F8-9FB2-8459B803C135.jpeg
     
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  11. YouTarzanMeJane

    YouTarzanMeJane

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    A close up of the fan wiring as I realised it wasn’t that clear before. Also thought it might be relevant to point out that it does have an isolator switch. C0B54492-5416-468A-8F5C-C9CE56FFC0DD.jpeg
     
  12. flameport

    flameport

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    Need to see wiring in that as well.

    What's missing is where the cables for the light and fan are connected together - none of the previous pictures show that.
     
  13. YouTarzanMeJane

    YouTarzanMeJane

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    Is that not one of the 3 cables going into the back of the light switch?
     
  14. YouTarzanMeJane

    YouTarzanMeJane

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    I’ve just discovered that, though we do technically have building regs approval, having a timer on an extractor fan in the room with no window is a requirement of the building regs so might get the builders back to fix it after all. .
     
  15. ericmark

    ericmark

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    I would think a PIR [​IMG] in a twin back box [​IMG] would likely be the easy way if you want it automated. For building regulations a pneumatic time switch [​IMG] is enough, the fan does not need to be automated, in fact when Part L first came out if there is a window which does not open using the lights alone was not permitted, it had to have a means to switch it on without the lights, but that requirement was removed. You can get the PIR with switch as well, what you fit will depend on if to just satisfy a building inspector or if needed to get rid of moisture.

    In the last 5 years I have lived in three houses, one had a problem with mould, the other two did not, and I thought about why, I realised it was down to the shower door or lack of, the house with problem shower was over the bath, so the glass door had a space below and above so the chimney effect caused the moisture to fill whole room, the others, one was a wet room so no cubical the other the door sealed at bottom so no through draft.

    The wet room did have a fan, but never used, the LABC building inspector insisted in spite of having an opening window since on the ground floor visitors could walk past the open window so he said it would not be opened so needed a fan, it drew that much air from the hall it made the wet room cold, so it was never used, and no mould.

    It seems odd, only the house which did not need a fan for building regulations, actually needed one to stop mould, maybe because the house was in Mold north Wales!
     
  16. EFLImpudence

    EFLImpudence

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    No, it isn't.
     
  17. YouTarzanMeJane

    YouTarzanMeJane

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