Viewing 17 posts - 1 through 17 (of 17 total)
  • Today's electrical/wiring question – Any sparkies offer advice?
  • dooosuk
    Free Member

    So I have an extractor fan in the bathroom of our flat. There’s an isolation switch above the door outside the bathroom. This is the only on/off switch for the fan. The Mrs doesn’t use it as she can’t reach it.

    https://goo.gl/photos/9yQbjTASjvj3d1Gn8

    Inside, I appear to have L1 (Red – Live), L2 (Yellow -Switch Live?) and Neutral (blue) (from the mains to the off side of the switch and again from the On side to the extractor). It seems the mains feed is connected to the same 6amp MCB on the consumer box that feeds the lights as the extractor doesn’t work if this is off.

    https://goo.gl/photos/FTwvyqpXRN9k7TGc7

    On the other side of the doorway is the bathroom light switch and so I was hoping I’d be able to poke the wire through and run 2 foot of cable along the door frame to the light switch as it’d still look quite neat.

    https://goo.gl/photos/NvKvtSGfLumuNjDq7

    However, from memory the switch only has 2 red wires and an earth (presumably live to switch and then live to light rose)

    All the wiring diagrams I have seen, seem to indicate the fan should be wired to the light lamp, not the light switch. Which obviously isn’t very easy to achieve.
    http://www.ultimatehandyman.co.uk/diy/electrics/extractor_fan/shower_fan_wiring-HARMONISED.jpg

    Is there a way to wire this into the light switch itself?

    The bottom two diagrams of this page, seems to indicate that it is possible:
    http://www.diynot.com/wiki/electrics:fan

    Looks like I might be able to change the Fan Isolator above the door for a fused switch and the pull cord switch for a DP version?

    Can’t even think of an easy way just to change the isolator switch to a pull cord or other switch type which she’d be able to reach.

    Any thoughts?

    wombat
    Full Member

    If you’re unsure about the wiring then the safest DIY way to deal with the issue would be to construct a small wooden box for the OH to use as a step. HTH

    sas78
    Full Member

    Brush or pole with a rubber end – reach for the stars!

    Fresh Goods Friday 696: The Middling Edition

    Fresh Goods Friday 696: The Middlin...
    Latest Singletrack Videos
    giant_scum
    Free Member

    The way you describe it the fan should switch on and off from the light switch!
    The Fan switch is effectively a triple pole isolator.
    The 3 core and earth cable at the fan isolator should be coming from the ceiling rose in the bathroom.
    Leave the fan isolator switch in the on position (unless you are working on the fan) because the fan will have a humdistat and a run on timer built in to it, probably.
    I see no problems here, leave it as is!

    dooosuk
    Free Member

    I see everyone is as defeatist as ever 🙂

    Edit – I see GiantScum was being helpful. Thanks

    mrmonkfinger
    Free Member

    This is the only on/off switch for the fan. The Mrs doesn’t use it as she can’t reach it.

    Does the fan come on when the light is turned on?
    And go off again 5 minutes after the light is turned off?

    If so, it’s all dandy, don’t touch nothing, leave the switch on, use the light whenever you’re in the bathroom.

    jimdubleyou
    Full Member

    Is it a fairly new house?

    The outlaws have this in their spare room – the fan stays on all the time. It’s rubbish.

    BigJohn
    Full Member

    I bet GS is right. If you’re going to poke about yourself I agree with the wooden box comment. But make it bigger and use it as a coffin.

    rwamartin
    Free Member

    Got a multimeter?
    As you say, fan should have live, switched live from the switch and neutral to it. These will be isolated in the 3 pole isolator.

    With the light switch off and the isolator off, test to see that there is a permanent live and a neutral (240 volts between them) and nothing between the switched live and neutral.

    Turn on the light. Check again. 240v permanent live to neutral but this time 240v switched live to neutral.

    Turn on the isolator and repeat the tests on the other side of the isolator.

    If all this is ok then the fan switch is ok and the wiring to and from the isolator is good. I would then suspect a faulty fan timer module.

    Report back!

    Rich.

    dooosuk
    Free Member

    Yep, I’ve got a multimeter so I’ll give it a check at the weekend.

    I think the thing that’s confusing me is that even with the light off, when I turn the isolator on the fan comes on.

    Thanks Rich.

    rwamartin
    Free Member

    Well, I’d check inside the fan to ensure the connections are correct. Permanent live might be in the switched live connector. This would cause it to run whenever the isolator was on.
    If the previous owner didn’t like the fan coming on with the light but wanted it to run on the isolator only this could be the way they’ve jury rigged it.

    Rich.

    tinribz
    Free Member

    Our downstairs loo has the same set up:

    Does the fan come on when the light is turned on?
    And go off again 5 minutes after the light is turned off?

    Yes and Yes. If you turn the isolator switch off the fan stays off otherwise the above.

    Sounds like someone has already been playing with the wiring, replaced the light switch incorrectly?

    dave_rudabar
    Free Member

    The bathroom fan in our old place was wired up similarly to yours. We had to use to the isolation switch as the on/off sw.
    It didn’t get used, we just left the window open on the vent latch!

    dooosuk
    Free Member

    Thanks for the pointers Rich.

    I’ll check the wiring at the fan and the light switch after running through your initial checks at the isolator at the weekend.

    rwamartin
    Free Member

    Doosuk,
    no problems. Give me a shout if you need any guidance.
    Rich.

    dooosuk
    Free Member

    All sorted thanks to Rich’s help.

    Confirmed isolator wiring all ok.

    Confirmed fan wiring wrong. Swapped live and switch live around and hey presto all works as expected.

    Thanks again for the help.

    rwamartin
    Free Member

    Result!
    Pleased to help.
    Rich.

Viewing 17 posts - 1 through 17 (of 17 total)

The topic ‘Today's electrical/wiring question – Any sparkies offer advice?’ is closed to new replies.