On 12/09/2014 05:59 AM, trader_4 wrote:

snip



Yep. That makes sense

He says that circuit also involves a half-bath and that it still
has power. It's possible that a GFCI in that bath has tripped
that serves the outlets in the bath and the 3 way light is downstream
of it?

If that's not it, then I'd check for voltage at the 3 wires going to
the switch. The switch is at the bottom of the stairs, so most likely
it's wired with the hot feed coming to the center pole of that switch,
light is connected to the center pole at switch at top of stairs.
See if there is 120V at the correct terminal, or 120V at all.

Finally, there is the issue of what kind of switches these actually are,
besides being square? The common, lower priced ones are just SPDT
switches, just like the old one. Higher end ones, eg Lutron Maestro,
use an electronic protocol between the switches, you need their devices
on both ends. IDK what happens if you just put one on one end, but given
that there is also no power in a bedroom, I doubt that's the problem.
Most likely, something is either wired up wrong, or else something came
loose, eg a pig tail was pulled loose from a wire nut, etc.




I just recalled that with a GFCI outlet (at least all the ones I have)
if you turn the breaker off at the box...the outlet will have to be reset.


Finally...I've only seen this once:

A circuit that was working, stopped working after I turned the breaker
off and later turned it back on. The breaker itself failed.