lighting circuits & wiring diagrams

3 way light switch using a two wire control



I’m including this method for reference in case you find it used in your house wiring but would not recommend this approach in a domestic environment. If you are adding wiring for a three way light switch then use the 3 wire control system.

I have detailed, quite extensively, why a two wire control system can be problematic in the article 2 way switch with 2 wire control. All the issues raised there apply here too, especially if used in stairways and the switches are on different floors.

This method is best suited to conduit/trunking based installations where single core conductors are used.

3 way light switch schematic diagram using a two wire control

3 way light switch schematic diagram using a two wire control

  • Pickle

    HELP!

    I have tried to change my lightswitch at the top of my stairs and completely mucked up. I had(i thought) written down where the wires went in the old switch but I have even tried to connect the old switch using that combination and it won’t work either. I have
    A two gang switch at the bottom of the stairs which switches on/off the dining room light and light at top of stairs
    A two gang switch at top of stairs (this is the one I am trying to change) which switches on/off the top of stairs light and landing light.

    Currently with all the wiring in as I wrote it down the switch at the bottom of the stairs is working as it should both dining room and top of stairs and the switch at top stairs is working as it should both top of stairs and landing light. But all the other lights upstairs will only work if the light at the top of the stairs is switched on whether that be from the bottom of the stairs or top.

    Please help I have been running up and down the stairs now for the last 3 hours trying different combos and this is the best I can get it 🙁

    Thanks in advance
    Pickle