Help with old 2 way lightswitch

[jbeav001]

I hope someone can help me please. I am replacing my old light switch for the stairs, both upstairs and downstairs switches

Upstairs I have a 2 way light switch.
This controls:

• The upstairs light
• The downstairs light

In addition, at the other end of the hall I have a 1 way switch which also controls the upstairs light.

Downstairs I have a 3 way light switch.
This controls:

• The upstairs light
• The downstairs light
• Outside light.

I've replaced light switches numerous times, but the stairs appear to be a dark art.

Upstairs
For upstairs, I have purchased an MK 2 gang 2 way light switch. The wiring seems a bit odd, as although its a double light switch, I appear to be short on the number of terminals I need. I effectively have three sets of wires coming into the existing old socket, but the new socket appears to only support 2 sets of wires. See attached drawing.

I'm wondering if I need to double up the cables into one of the terminals, otherwise I am short of a terminal pair. Maybe the set that has the joined reds.

I have a similar issue for downstairs but want to tackle one at a time.

Thanks in advance.

JB

 

[littlespark]

The switch with 4 terminals is an "intermediate" switch.... You have one light that can be controlled by 3 switch locations.

If you can get a 2 gang switch with a 2 way and an intermediate... or you might need to build one up from grid switch modules.

 

[jbeav001]

The switch with 4 terminals is an "intermediate" switch.... You have one light that can be controlled by 3 switch locations.

If you can get a 2 gang switch with a 2 way and an intermediate... or you might need to build one up from grid switch modules.

Thanks, I had never heard of an intermediate switch but having looked I managed to get some Lieber branded ones ordered. I imagine that's my downstairs issue too so ordered both.

 

[brianmoooore]

An intermediate switch is used for light that is controlled from three locations. Only one intermediate switch is used, with the other two being ordinary two way switches, the same as used for lights controlled from two locations.