Confusing Dimmer Switch Wiring

[bounder0121]

Hi

I've been looking to replace a dimmer switch that causes lights to flicker (even when on full) — all the replacement switches I've looked at seem to have L1 L2 and one other connector.

The switch has two sets of wiring coming into the box — earth & then two black wires and two red wires. One of the red wires was not connected to anything and is taped up.

If I wire the two blacks into L2 and the red into L1 as suggested by an electrician mate the dimmer switch has no effect at all (although the second switch controls the light on/off)

If i copy (as close as possible there were no markings I could see on the old switch) the layout on the old switch the dimmer works but buzzes and flickers. I've currently got it all switched off (not a huge problem) - but I'd like to sort it.

Have attached a diagram

Untitled

• bounder0121
• 25 Nov 2013
• 1

 

[ban-all-sheds]

What type of lamps are you trying to dim?

There may not be a problem with the dimmer switch at all....

 

[bounder0121]

It's a 'normal' light in the ceiling—with a standard 40W bulb in it. There doesn't look to be any connection problems in the fitting—and like I say with the dimmer wired 'out of the equation' the secondary switch works fine and the light is on without flicker.

i'm assuming that the old dimmer switch worked at some point for the previous owners…

 

[ban-all-sheds]

If I wire the two blacks into L2 and the red into L1 as suggested by an electrician mate the dimmer switch has no effect at all (although the second switch controls the light on/off)

Which is what one would expect. It's pretty mind-boggling that an electrician would tell you do do that.

See the top-left diagram here: //www.diynot.com/wiki/electrics:two-way-lighting

If i copy (as close as possible there were no markings I could see on the old switch) the layout on the old switch the dimmer works but buzzes and flickers.

Flickering etc aside, does it work as you'd expect, i.e, you still have 2-way control with the dimmer and the other switch?

It's a 'normal' light in the ceiling—with a standard 40W bulb in it.

40W should be enough, but you have checked what the minimum & maximum loads are ?

There doesn't look to be any connection problems in the fitting—and like I say with the dimmer wired 'out of the equation' the secondary switch works fine and the light is on without flicker.

What do you connect together when you take the dimmer out?

i'm assuming that the old dimmer switch worked at some point for the previous owners…

So has it never worked for you?

 

[bounder0121]

If i copy (as close as possible there were no markings I could see on the old switch) the layout on the old switch the dimmer works but buzzes and flickers.

Flickering etc aside, does it work as you'd expect, i.e, you still have 2-way control with the dimmer and the other switch?

Yes… but very flickery and buzzy…