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Dimmer switch fubared

rousetafarian

Moderator
Hi

One dimmer switch and 8 ceiling (GU10) lights I’m the bedroom....all of the bulbs work in other sockets and I’ve reset the fuse box.

Assuming something is faulty with the physical switch itself, are they easy to replace and will I survive having zero electrical works knowledge?

Thanks
 

LV426

Administrator
Staff member
Yes, easy.

Typical single switch installation:

1: TURN OFF POWER. Remove relevant fuse or trip the breaker in your consumer unit.
2: Remove two external screws and pull the switch out of the wall
3: There are likely two wires at the switch (Live supply, Switched Live to lamp), plus probably an earth which may be attached to the wallbox itself, or to a very visible metal strip on the back of the switch. TEST the live wires to ensure they are not live (i.e. you flipped the right breaker or removed the right fuse).
4: Unscrew holding screws and disconnect two wires.
5: Loosen the holding screws in the new switch and offer it to the hole. Connect the two wires. It typically doesn't matter which goes where, but if they are similarly labelled on the old and new switches, connect them the same way. Tighten the holding screws.
6: Push the switch into the hole and replace the two external screws.
7: Power on and test.

If there are any more wires (beyond two and earth) then this may be a two-way setup and then the polarity will matter. In such a case, the Live supply wire needs to go to the "common" terminal. The other two can be either way around. Inspect the positions of cables in the old switch to establish which is the common (Live supply) cable.
 

RBZ5416

Distinguished Member
Assuming that this has stopped working rather than newly fitted switch or lights, then a piece of cake. Two screws for the faceplate & two terminals inside. Just make sure you turn off the power first.

Might even just be a loose connection that wants tightening before you buy a replacement.

 

RBZ5416

Distinguished Member
Just an addendum, smart light switches require a neutral wire also. Discussion of these suggests that newer properties have this also running to the switch. But if present will likely be two blue wires joined together but no connected to the switch itself.
 

Wahreo

Distinguished Member
Are they LED GU10’s?

if so then the dimmer needs to be one that is suitable for LED’s. Not all of them are.
 

rousetafarian

Moderator
401346A6-8E64-417C-AC2B-8AC072C8959F.jpeg



Three wires go into one and one into the other.....?
 

RBZ5416

Distinguished Member
Not great as the switched live should be marked with sleeving or tape. Not a great problem but just make sure you mark the single wire somehow before disconnecting, so it doesn't get mixed up with the others. Then just wire the replacement like for like.
 

LV426

Administrator
Staff member
Just replicate what's there already. Same 3 into one, same one into the other.
 

rousetafarian

Moderator
Hi these aren’t LED GU10’s, so I took the switch cover off and was faced with this

3EB53961-C5E6-428A-9C24-331F1FB02515.jpeg


Unscrewed the pair of screws (one had one wire going into it and other had 3 Wires) the what I can only describe as a copper coil (resistor?) was loose under the blue casing. Realised I was out of my shallow depth so taped up the 3 wires and screwed the fascia back in, and walked away.

I guess a new 60-250w dimmer switch module alone or if I buy a new dimmer switch from say B&Q would it come with a module and I just rewire it the same way.

This switch is from 2004 It would seem.

Thanks
72A02D35-A977-4E6C-98B1-1F419C1CA791.jpeg
 

rousetafarian

Moderator
As @Wahreo said, what lamps are in the fittings? Is there power at the switch. Have you an ordinary switch to try and see if it’s something other than a faulty dimmer switch?

Ensure you follow safe isolation.
Non-led GU10 x 8 and no alternative switch to try I’m afraid
 

ufo550

Well-known Member
If you have halogen lamps, its quite common when one of them blows as you turn on the dimmer, it causes a power surge, which can destroy the dimmer. A quality dimmer has a 'soft start' mode to prevent this.

Didn't think anyone used halogen lamps these days :)

Varilight do some good dimmers, this is their compatibility list, they can be sourced from Screwfix. If you have a test lamp, I would check there is power at the switch to rule that out.
 

LV426

Administrator
Staff member
Your copper coil is, I suspect (without seeing it) a component of the broken dimmer switch.
 

rousetafarian

Moderator
The update you’ve undoubtedly been waiting for....I didn’t electrocute myself because I felt more comfortable letting a local contractor come and do the jobs needed

Called him yesterday, arrived here today all sanitised and boot covers on and came recommended from my Dad.

20 X halogen GU10’s replaced with 4 watt Fusion LEDS, a nice warm dimmable White too. A new 3 gang (grid?) dimmer for the lounge and a Newsingle dimmer for the bedroom.

We actually fitted 2 sets, as he wasn’t happy with the protruding Aurora ones we first set up, so the job has been done properly.

All in all £150.00 well spent in my book.
 

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