By detecting dangerous current
flow and instantly shutting off
power, ground fault circuit
interrupters save hundreds of lives
each year. But after 10 years or so, the
sensitive circuitry inside a GFCI wears
out. And usually the test button on the
GFCI doesn't tell you there's anything
wrong: When you press the button, it
shuts off the power as always. So the
only reliable way to check an older
GFCI is to use a circuit tester that has
its own GFCI test button ($10 at home
centers and hardware stores).
Plug in the tester and push its test
button. If the power goes off, the GFCI
is working. Press the reset button to
restore power. If the power doesn't go
off, replace the GFCI.
Your new GFCI ($9) will never
require a circuit tester. All GFCIs manufactured
after mid-2006 are designed
to tell you when they fail. The vast
majority indicate failure by shutting
off power permanently. So someday
your GFCI (and any other outlets connected
to it) will simply stop delivering
power and you'll have to replace it.
