Outdoor GFCI Outlet Keeps Tripping After Rain? (Fix It Now!)

Any outdoor electrical circuit should be protected by a GFCI breaker somewhere in the circuit. GFCI circuits protect you from an accidental shock be interrupting the flow of electricity when an electrical fault is detected. Sometimes, an outdoor GFCI outlet will trip after a rainstorm.

In most instances, moisture in the electrical box housing the GFCI breaker is the cause for the GFCI breaker tripping. The problem is not with the GFCI outlet. More than likely, the problem is the location or the condition of the box housing the outlet. Other conditions may cause the GFCI outlet to trip, but these conditions are rare.

A GFCI circuit breaker outlet that is not operating correctly is a hazard. You should address this problem quickly. In many cases correcting this problem safely requires the services of a licensed electrician. GFCI breaker outlets are not repairable. If the GFCI outlet is the problem, the only safe repair is to replace the outlet.

In simple terms, a GFCI is a circuit breaker built into an electrical outlet. If the GFCI senses a ground fault in the circuit, the GFCI quickly trips and stops the flow of electricity to the outlet. This interruption happens within 1/40th of a second when the GFCI senses a ground fault.

GFCI outlets constantly monitor the flow of electricity in the circuit. If the difference in the power going into and coming out of the circuit is more than five milliamperes, the GFCI interrupts the circuit.

GFCI outlets are not without their problems. Understanding how GFCI outlets work is a big part of diagnosing when and where problems can occur. Typically, GFCI circuits exist in areas that are prone to moisture. Many building codes require GFCI outlets in bathrooms, laundry rooms, kitchens, and other indoor spaces where moisture or water creates a hazard.

Any electrical circuit installed outdoors requires a GFCI outlet in the circuit. Most building codes specify that the electrical wiring is protected by waterproof conduit and electrical boxes as well. Sometimes these outdoor installations present problems that can cause a GFCI outlet to trip.

Perhaps the most common cause of a GFCI outlet tripping after a rain is water where water shouldn’t be. A typical outdoor installation for a GFCI outlet is in waterproof electrical boxes that include a cover that keeps rain and other moisture from getting into the electrical box.

If moisture gets inside the electrical box, the outlet may begin to leak power to the ground wire, or it may be finding a path to ground outside the electrical wiring. In either case, the GFCI outlet is working as it should.

You may be able to diagnosis this problem yourself. A few simple steps can help you find an outlet part of the GFCI circuit and is grounding due to moisture.

Finding the outlets on a GFCI circuit may be easy if the GFCI circuit has tripped. One GFCI circuit can protect several outlets. If your GFCI outlet is tripped, you can check other electrical boxes and outlets using a voltmeter, a circuit tester, or a live circuit probe. These tools are not expensive and are available at most of the big box home improvement stores.

For your safety, always turn off the circuit breaker at the service panel before working on any electrical circuit. Even though the GFCI outlet is tripped, you should turn off the breaker. Turning the circuit breaker off prevents any power to the circuit.

The easiest way to dry out an electrical box that you suspect has moisture is with a hairdryer. Use the hairdryer set on its lowest setting. Play the warm air into the electrical box and over the outlet. Be careful not to get the hairdryer to close or you risk melting the electrical box if it is plastic or the insulation on the wires.

Do this with each electrical outlet box in the circuit protected by the GFCI outlet. Dry out the GFCI box as well. Take your time and make sure that the boxes are completely dry and free of moisture.

Restore the power to the circuit by turning the circuit breaker on at the service panel. Next, carefully reset the GFCI outlet by pressing the reset button. If all is well, power this will restore power to your GFCI protected circuit.

If your GFCI outlet trips immediately, moisture in your electrical circuits is probably not the problem. It would be best to turn off the power at the circuit breaker and call a licensed electrician to find the problem and correct it.

If drying out the boxes seems to work, the culprit is probably a water leak allowing excess moisture into one of the electrical boxes. Examine each of your waterproof electrical outlet boxes. These boxes should have covers with seals that protect the outlet inside from excess moisture.

Check the box and the box lid for cracks or other damage that can allow water to enter. Open the lid and check the foam seal around the edges. These seals are easily damaged or lost if you use the box regularly. Replace the seals if damaged or missing.

Often homeowners will install a GFCI outlet in an old outdoor circuit on older homes. While adding a GFCI outlet to a circuit is a good idea, the downstream parts of the wiring may be incompatible with the GFCI outlet. Incorrect wiring can cause problems that may result in intermittent interruptions in the circuit by the GFCI outlet.

Correcting wiring problems associated with installing a GFCI outlet in an older wiring system should be done by a licensed electrician. Many times, correcting these sorts of problems requires running additional wire or upgrading the wiring in the circuit.

In the end, if all the other options are exhausted, you may have a bad GFCI outlet. GFCI outlets are susceptible to damage like any other outlet. Pulling or jerking on cords attached to the outlet can break the housing and cause problems. The circuits inside that outlet that sense the voltage in the circuit can fail.

A visual examination of your GFCI outlet will often reveal any physical damage. Any GFCI outlet with visible damage such as cracks, scorch marks, or other visible damage should be replaced immediately.

Internal damage to the circuitry is harder to evaluate. Our recommendation is to replace the GFCI outlet if there is any question about its condition. There are ways to test a GFCI circuit beyond the test button on the outlet. However, these kinds of tests present their dangers, and we don’t recommend that homeowners try to administer these tests. Call an electrician or replace the GFCI outlet with a new outlet.