My GFCI test button won’t push in when I try to reset it, but nothing has tripped in the breaker box, and the hairdryer works when I plug it into outlets down the hall. Why won’t my GFCI reset?

See? Good and evil. An RCD (or GFCI in the States) is a kind of circuit breaker that trips when the amount of current in the hot and neutral mains power lines aren’t equal and opposite ...

The outdoor outlets and bathroom lights didn't work. I knew enough to check for tripped circuit breakers and GFCI outlets. But I couldn't find the problem. I was just about to start pulling apart ...