Dimmer - replacing a 2 way switch with a one way dimmer

[reynoldo]

I have bought a Wilko one way dimmer switch to replace an existing two way light switch in my lounge. The reason I have bought a one way dimmer is that there must have been wall lights in the room at one point (before my time) which are no longer there - hence one of the switches on the existing switch is redundant. Having looked at how the existing switch is wired up I am somewhat confused.

All the wires into and out of the existing switch are red.
Although there is a redundant switch both are wired up still.
There appears to be some sort of jump connection on the back of the existing light switch.

What do I do with the "redundant" (but possibly still live!) wires?

The only solution I can come up with is to put a two way dimmer switch in instead and have a redundant knob (so to speak). At least then I can replicate the existing wiring and connections.

Any help appreciated.

Thanks

Dim and dimmer

 

[ban-all-sheds]

I have bought a Wilko one way dimmer switch to replace an existing two way light switch in my lounge.

No - you've bought a one-gang dimmer switch to replace an existing two-gang switch.

All the wires into and out of the existing switch are red.

If that confuses you then PLEASE go away and learn about house wiring before attempting to fiddle with it.

Although there is a redundant switch both are wired up still.

So somewhere you've got a switched live cable running off that's no longer connected to any lights.

Lovely.

I wonder what's been done to the end of the cable, and if the cable is buried in walls somewhere it shouldn't be?

There appears to be some sort of jump connection on the back of the existing light switch.

Commonly done - one permanent live to the switch, more than one switched live from it.

What do I do with the "redundant" (but possibly still live!) wires?

Assuming you're not the sort of person who thinks that he can use the point of a knife instead of a screwdriver, or the heel of a shoe instead of a hammer, then you should have a multimeter, as it's an essential tool if you want to do anything with the wiring in your house except just use it.

And with the meter you can determine which wires are permanently live and which are switched - you've almost certainly only got one permanent one there.

The only solution I can come up with is to put a two way dimmer switch in instead and have a redundant knob (so to speak). At least then I can replicate the existing wiring and connections.

But then you'll be replicating the situation of a switched live wire going who knows where, with who knows what done to the bare ends. Don't connect it up.

Any help appreciated.

//www.diynot.com/forums/viewtopic.php?p=75416#75416

 

[holmslaw]

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[reynoldo]

Yes thanks - will have a look again tonight.

 

[reynoldo]

Holmslaw,

Just had another look at the exisiting wiring. The old switch is wired up as follows:

Top

Acom (bridged to Bcom)
B1
B2 Empty

Bottom

A1
A2 Empty
Bcom (Bridged to Acom)

The new dimmer has L1, L2 (no screw) and C

Therefore I have 2 surplus wires not one. I tried connecting it up and insulated the two surplus wires. The good news - the dimmer worked. The bad news I lost other lights downstairs! When I reconnected the old switch as it was before all lights worked OK......

 

[ban-all-sheds]

PLEASE go away and learn about house wiring before attempting to fiddle with it.

 

[holmslaw]

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