The heat finally breaks, and holiday lights start going up across Queen Creek and the East Valley. Then, a night later, half the display is dark and the outdoor outlet has clicked off again. You reset it, and it trips again.
Short answer: An outdoor GFCI usually keeps tripping because it detected electricity leaking to ground, most often from water in a plug, cord connection, light string or the outlet box. Damaged decorations, too much load on one circuit and worn-out GFCI outlets come next. Find the wet or faulty piece, and never bypass the GFCI.
Here’s why it happens, how to find the cause yourself, and when to call an electrician.
What does a GFCI outlet actually do?
A GFCI (ground-fault circuit interrupter) watches the electricity going out on one wire and coming back on the other. Those two should match. If even a tiny amount goes missing, roughly five thousandths of an amp, the GFCI assumes that current found another path to ground. That path could be water, or it could be a person. It shuts the power off in a fraction of a second.
That’s why local electrical codes, based on the National Electrical Code (NEC), call for GFCI protection on outdoor outlets at homes, along with weather-resistant outlets and “in-use” covers that stay closed while something is plugged in. A GFCI that trips is usually not broken. It’s telling you something on that circuit isn’t right.
The GFCI doesn’t have to be on the outlet you’re using. Outdoor outlets are often protected by a GFCI in the garage, a bathroom or on another outside wall. If your outdoor outlet is dead and has no buttons, look for a tripped GFCI elsewhere first.
Why does my outdoor GFCI keep tripping?
Here are the usual suspects, roughly in the order we find them:
- Water in a cord connection. Two plugs joined together and lying in grass, gravel or a puddle is the classic cause.
- Sprinkler and drip-line overspray. An irrigation head that sprays the wall outlet, the extension cord or a lit-up bush can trip the GFCI every time the timer runs.
- A missing, cracked or open outlet cover. Flat covers that only close when nothing is plugged in let rain and sprinkler water straight into the outlet.
- A damaged light string or decoration. A cracked socket, pinched cord or wet inflatable can leak on its own.
- Too much on one circuit. Inflatables and light strings add up fast, especially if the circuit also feeds the garage.
- A worn-out GFCI. These are electronic devices. Outdoor ones take a beating from sun, heat and dust, and they don’t last forever.
- A wiring problem. Water in the box behind the outlet, corroded connections or damaged wiring downstream can cause trips with nothing plugged in at all.
Why do holiday lights trip the GFCI so often in Arizona?
We don’t deal with snow, but Arizona has its own recipe for holiday trips:
- Fall watering. Many East Valley lawns get overseeded in the fall, so sprinklers run more often right when decorations go up.
- Winter storms. A cold rain after weeks of dry weather finds every open plug and cracked cord in the yard.
- Sun-baked gear. Cords and covers left outside all year, or strings stored in a hot garage, get brittle and crack.
- Long run times. Displays often run every night for weeks, so a small leak or a heavy load eventually shows up.
How do I find what’s tripping my GFCI?
You can usually track it down in a few minutes. Work during the day, keep your hands and the outlet dry, and don’t open any outlet boxes.
- Unplug everything from the outdoor outlet and any other outlets on that circuit.
- Press RESET on the GFCI. If you can’t find it, check the garage, bathrooms and other outdoor walls, then check the breaker in your panel.
- If the GFCI won’t reset or trips with nothing plugged in, stop here. That points to water in the box, a failed GFCI or a wiring fault, and it’s time to call an electrician.
- If it holds, plug decorations back in one section at a time and wait a few minutes between each one. If the trips seem to follow the watering schedule, look at what the sprinklers hit, but never spray or wet anything that’s plugged in.
- When it trips, you’ve found the problem section. Leave it unplugged, and don’t touch plugs or cords while they’re wet or still plugged in. Once it’s unplugged and dry, check for cracked sockets, damaged cords or connections lying on the ground, and throw out any damaged strings. If you can’t find a clear cause, or it keeps tripping, stop and call an electrician. A GFCI that keeps tripping is warning you about a real problem, and Randy can test the circuit safely.
A wet plug can take a day to dry out after rain. Skip the electrical tape and plastic bags around connections. They tend to trap moisture instead of keeping it out.
How much can I plug into one outdoor outlet?
Most home outlet circuits are 15 or 20 amps, and your outdoor outlet probably shares its circuit with other outlets. Add up the watts printed on the tag or box of each light string, inflatable and decoration. A common rule of thumb for anything that runs for hours, like holiday lights, is to stay around 80 percent of the breaker’s rating or less.
LED strings use far less power than old incandescent ones. For bigger displays, spread the load across more than one circuit, and follow the manufacturer’s limit on how many strings connect end to end.
Can I just replace the GFCI with a regular outlet?
No. A GFCI that keeps tripping is catching the kind of leak that can shock someone standing on damp ground. Swapping in a regular outlet doesn’t fix the leak. It just removes the protection. Fix the cause, or have us replace a worn GFCI with a new weather-resistant one.
Quick checklist: outdoor outlets and holiday lights
- Test each GFCI with its TEST and RESET buttons before you decorate.
- Make sure every outdoor outlet has an “in-use” bubble cover that closes over a plugged-in cord.
- Use outdoor-rated extension cords and light strings only.
- Keep every cord connection off the ground and out of sprinkler spray.
- Toss strings with cracked sockets, pinched cords or brittle insulation.
- Add up your watts and split big displays across more than one circuit.
- Never remove, bypass or tape over a GFCI.
When should I call an electrician?
Call us if any of these sound familiar:
- The GFCI won’t reset, or trips with nothing plugged in.
- It keeps tripping even after everything is dry and covered.
- The outlet, cover or plug feels warm, looks scorched or smells like burning plastic.
- Water has gotten inside the outlet box, or the box is loose from the wall.
- The breaker in your panel trips along with the GFCI, or other parts of the house lose power.
- You don’t have a GFCI or an outdoor outlet where you need one.
If you see sparks or smoke, turn off that breaker if you can do it safely and call us. We answer emergency calls 24/7, so call our emergency electrician line any time. If there’s fire, get out and call 911. If your whole house or street is dark, check with SRP or APS for an outage before you call.
What can an electrician add before the holidays?
Our electrical troubleshooting and repair service finds the real cause instead of guessing. Common fixes and upgrades include:
- New weather-resistant GFCI outlets with in-use covers.
- A dedicated outdoor circuit so your display isn’t sharing power with the garage freezer.
- Outdoor outlets where you need them, like under the eaves, so cords don’t cross the driveway.
- Switch, timer or app control through our lighting installation and Lutron lighting controls work.
- Permanent roofline lighting, so you can skip the ladder (see our permanent lighting post).
- GFCI checks near pools and spas through our pool, spa and hot tub electrical service.
If adding circuits shows your panel is already full, we’ll explain your options honestly, including a panel upgrade if you actually need one. We coordinate SRP and APS disconnects and reconnects for that work, so you aren’t stuck in the middle.
Serving Queen Creek and the East Valley
We’re based in Queen Creek and help homeowners in San Tan Valley, Gilbert, Mesa, Chandler, Florence, Scottsdale, Apache Junction and Gold Canyon, Sun Lakes, Tempe, Cactus Forest, Coolidge, Paradise Valley and Ahwatukee. Regular hours are Monday through Friday, 6 AM to 6 PM, and we answer emergency calls 24/7.
Frequently asked questions
Why does my outdoor GFCI trip only when it rains or the sprinklers run?
Water is reaching a plug, cord connection, decoration or the outlet box on that circuit. Lift connections off the ground, keep them out of sprinkler spray and use a closed in-use cover. If it still trips once everything is dry, have an electrician check the box and wiring.
Why do my Christmas lights trip the GFCI after a few hours?
Usually moisture builds up in a connection, or a damaged string starts leaking once it gets damp. It can also mean too much is on one circuit. Test one section at a time, and spread large displays across circuits.
Why won’t my outdoor GFCI reset?
Make sure the outlet still has power by checking the breaker and any other GFCI that may feed it, like one in the garage or a bathroom. If it still won’t reset with nothing plugged in, there may be water in the box, a failed GFCI or a wiring fault. Leave it off and call an electrician.
Can I replace a tripping GFCI with a regular outlet?
No. Outdoor outlets at homes need GFCI protection under local electrical codes, and a GFCI that trips is protecting you from a possible shock. Fix the cause, or have an electrician replace a worn GFCI with a new weather-resistant one.
Do I need a dedicated circuit for holiday lights?
Not always. Small LED displays usually run fine on an existing outdoor outlet. Large displays, inflatables, or outlets sharing a circuit with the garage often do better on a dedicated circuit. An electrician can check your load.
How often should I test my GFCI outlets?
Many manufacturers recommend testing GFCIs monthly. Press TEST and the power should cut off, then press RESET. Test outdoor GFCIs before you put up holiday lights. If one doesn’t trip when tested, or won’t reset afterward, have it replaced.
Outdoor outlet giving you trouble? Call Randy
Henderson’s Electric Solutions LLC is a family-owned electrical contractor in Queen Creek, owned by Randy and Tori Henderson. Randy is our licensed electrician (ROC CR-11 #341452), and we’re bonded, insured and BBB accredited. We come with the solution, not excuses, whether it’s one outdoor GFCI or a new circuit for your display.
Call Randy at (480) 430-2775, email info@hendersonselectric.com, or request an estimate online. Solutions Only - No Excuses.