Switch Turns Off But Not On

Question

Lights can be turned off or dimmed, but not turned on from the X10 powerline signal. Any ideas as to what causes this?

Modules can be turned off but not turned on from the X10 powerline signal. What might cause this?

Answer

This problem is most likely caused by line noise. The noise on the line stops the X10 signal from getting through so you can't turn the light on. BUT if you turn the light on from its push button, it puts a load across the line that attenuates the noise, so now you can dim or turn off the light. As soon as you turn it off, and remove the load, the noise pops back up. You need to determine the source of the noise and filter it.

This can be particularly prevalent in 3-way switches since there can be noise on the traveler wires, which is much more difficult to get rid of. In these situations the easiest fix is to forget about the companion switch and instead attach an SS13A to the wall in that location, and use that instead. This requires a TM751, PS561, RR501, or CM15A transceiver.

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