Last night we had a good rain storm and an exterior GFCI outlet tripped. That outlet is controlled by a switch in my foyer and is used to turn walkway lights on or off. The test button of the outlet is depressed, and pressing the reset button doesn't do anything. It just springs back when pushed. The light on the GFCI outlet is illuminated. I checked the circuit breaker and it wasn't tripped, but I turned it off and back on anyway but that didn't change anything. Since this is an exterior outlet controlled by a switch I don't believe that there's anything downstream from it.
There are really only two likely possibilities here:
- Broken GFCI
Repeated trips, dirt, water damage, insects, loose connections leading to arcing - there are a ton of reasons why a complex electronic device like a GFCI can fail. They are designed to fail safe when possible - i.e., off rather than on. If the GFCI has truly failed, the only fix is to replace it.
If you have to replace it, you may want to consider an inside location so that the outside receptacle is a simple receptacle and therefore less likely to fail due to weather and other "outside" problems. One possibility is to replace the switch with a GFCI switch like this one:
and then you can use a simple weather-resistant receptacle outside. Whatever you do, make sure you have a good in-use cover over the receptacle.
It is quite possible that water got into the GFCI/receptacle in a way that it causes a ground-fault (which is why the GFCI won't reset) and doesn't quickly dry out. If that's the case, you can either remove it to dry it out or just wait a day or two. If after it dries out, everything works properly (TEST/RESET work and power only when the GFCI is not tested or tripped) then you are fine. In other words, the GFCI may simply be doing exactly what it is supposed to be doing.
STOP. GFCIs don't just protect the 2 sockets. They can also protect wiring attached to them, and it's generally smart to use that feature to protect downline wiring, so you need fewer GFCI devices. A fault in that wiring will cause the GFCI to trip, and that is working as intended.
So you can never condemn a GFCI until you pull it out and disconnect all wires on the "LOAD" terminals. Otherwise you're doing the equivalent of testing a smoke detector in a smoke-filled room.
If the GFCI behaves properly after the "Load" wires are removed, then the GFCI is doing its job, and there's a genuine ground fault in the downline wiring. Detecting that is why you installed a GFCI, so now you can fix it without having to attend a funeral first :)
My great-great grandfather never installed a GFCI outside in the weather. So I advise manassehkatz's strategy of "move the GFCI indoors".