2 Gang to 1 gang dimmer switch wiring advice

11 Mar 2021
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United Kingdom
I've been trawling about 25 threads for an answer to what I hope is a really simple question about how I replace a 2 gang switch, which currently controls two seperate hanging light fittings in my lounge, to a single dimmer switch.
I don't want to control the lights independently any more as they're only six feet apart in a small living room. but I'd like to brighten and dim both lights simultaneously with the one gang dimmer.

The current 2 gang switch has a single red, blue and yellow wires going into it and there is a bridging wire between the red wire port and another port.

I thought this would be really simple but I can get it to turn on one light or the other but not both at the same time. The dimmer switch has a L1, L2 and switching port. Or is a single dimmer switch simply not capable of controlling six bulbs (3 in each light fitting)?
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Red into the "Switching port" (usually called common), blue and yellow together into L1. Leave L2 empty.

If it works with 6 bulbs depends on the rating of the switch and the total load (Add up the Watts of each bulb)
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For future visitors to this thread, take care to match the dimmer to the load, not just wattage-wise but also the type of load. LED lamps cannot be dimmed by a standard dimmer and vice versa. If in doubt, contact the dimmer manufacturer for advice.

Doyle and Tratt have a great range of dimmers for most purposes and gave a fantastic technical dept.


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