I have corridor lights (12 of them) linked up to two 3-way dimmer's. The lights were dimmable from both sides and all worked fine. After replacing some connections in the bathroom (separate to the corridor), I noticed the hall lights would not switch on.

More specifically, they would switch on for a split second before dimming down. The time it would switch on for has decreased rather dramatically, with the lights being on for barely half a second before switching on.

I had a look at one of the dimmer, and it seemed the internals were completely broken, so I had the dimmer replaced but they dont seem to switch on. Removing the dimmer (the replacement one) and connecting the red wire to the blue wire, the lights switch on.

I had triple checked my wiring when replacing the dimmer; red going to live, yellow going to slave, blue going to the other one. This is also in occurdence to the other dimmer.

How would I go about troubleshooting this and what could be possible causes for this behaviour (and fixes)?


  • Do the instructions for these dimmers actually specify that two dimmers can be used together? What is the model number of each dimmer? – Harper - Reinstate Monica May 22 '19 at 15:33

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