If power is lost to lights or receptacles, and a circuit breaker is not tripped, it may be a tripped GFCI receptacle. A tripped GFCI receptacle may cause a standard receptacle to lose power. Power to receptacles or lights in a bathroom may be supplied from an GFCI receptacle in the same or another bathroom, or the garage.
If the GFCI receptacle continues to trip after resetting, there may be a problem with something that is plugged in, or a bad GFCI. If there is no power coming out of the GFCI, but a good 120 V and neutral going into it, the GFCI will need to be replaced.
For information on locating these receptacles, see the GFCI configuration page.
When a house is being sold, there is usually a home inspection related to a mortgage or a home warranty. Electrical inspections usually check for GFCI receptacles in required locations including kitchens and bathrooms.
When preparing for a home inspection, someone may replace standard receptacles with GFCIs in the bathrooms or kitchen, not knowing that they are already protected by a GFCI load in a different location. This can cause GFCIs to trip frequently.
Normal GFCI line load configuration GFCI connected to the load of another GFCI
A GFCI receptacle can trip frequently for the following reasons.