Talk:Noise on 3-way Traveler Wires
Had the same problem using WS14's (being able to turn lights off but not on). I found that connecting 12 gauge solid copper wire into the switch terminals caused the wallswitch to flex in such a way to cause this problem. Had to connect smaller gauge (14) wire to switch terminals then wirenut these wires to the 12 gauge solid wire. This solved the problem.