"Dave Morrison" wrote in message
...
nr wrote:
Thanks for the responses. The GFCI receptacle is in a bathroom. When
it is working, I've run a heater with no problems. The wires are run
through the attic. I spoke with my electric company yesterday and was
advised it might be a loose ground connection and that maybe it only
happened after a heavy rain. I don't remember the previous conditions
but Thursday we had heavy rains and the GFCI tripped and wouldn't
reset, but Friday afternoon, after things had dried out, it reset fine.
Now I have to find where the ground connection is.


The GFI is probably protecting some other outlets down stream, very
common. The rain problem makes me suspect that is protecting an outdoor
receptacle. Check your outdoor outlets, if you find one with no power make
it rain proof.
Dave

If i understand correctly GFCIs operate when there is some sort of unbalance
between the current flowing to the appliance on say the live wire and
returning from the appliance through the neutral wire.
This condition could include a leakage to ground from something live, such
as a damp/faulty outlet or something switched off but faulty, plugged into
the GFCI outlet itself or to another 'downstream outlet protected by the
GFCI.
For example we have a GFCI inside the garage but it also protects one other
'outside' outlet on an outer wall. The snap cover of the outside outlet
failed to close, snow got into the outlet and melted. GFCI operated as it
should probably due to leakage through dampness to the grounded metal wall
box.