TL;DR

  • The most common cause of a tripping breaker is circuit overload — too many devices on one circuit (a 15-amp breaker only handles 12 amps sustained).
  • Six-step home diagnostic: identify the breaker, do a clean reset, unplug everything on the circuit, check for overload, check for short circuits, and rule out AFCI nuisance trips.
  • If the breaker trips with everything unplugged, the problem is in the wiring itself — that requires a licensed electrician.
  • Never force repeated resets on a tripping breaker. If you smell burning, see sparks, or feel heat at the panel, shut off the breaker and call immediately.

The most common reason a breaker keeps tripping is circuit overload — too many devices drawing more current than the breaker’s 80% sustained rating (12 amps on a 15-amp breaker, 16 amps on a 20-amp). A breaker that trips once might mean nothing. A breaker that trips repeatedly always means something — and what it means matters because the wrong response (forcing repeated resets) makes the actual problem worse.

Here’s a six-step diagnostic you can do in 15 minutes before deciding whether to call us.

Stop and call immediately if any of these are happening:

  • Burning smell from the panel, an outlet, a switch, or a wire
  • Sparks or arcing visible at any device
  • Smoke from the panel or any electrical equipment
  • A breaker, switch, or outlet that’s hot to the touch
  • Visible scorch marks or melted insulation

These are not “diagnose at home” situations. Shut off the affected breaker if you can do so safely, leave the rest of the panel alone, and call our 24/7 emergency line at (858) 400-8901.

For everything else, read on.

Step 1: Identify which breaker is tripping

Open your panel and find the breaker that’s not fully in the ON position. Tripped breakers sit in a middle position — not fully ON, not fully OFF. You’ll feel a click when you flip them fully OFF, and a different click when you push them fully ON.

Make a note of which breaker it is and what’s labeled (panel directories are often wrong, but it’s a starting point).

Step 2: Try a clean reset

To reset a tripped breaker correctly:

  1. Flip it fully OFF first (push the handle all the way toward OFF, you’ll feel a click)
  2. Wait 5 seconds
  3. Flip it fully ON (push fully toward ON)

If the breaker holds, see if it trips again under normal use. If it doesn’t trip, you’re done — but pay attention to what was running when it tripped originally. That’s a clue.

Step 3: Unplug everything on that circuit

If the breaker trips again, here’s the cleanest diagnostic you can do at home:

  1. Reset the breaker
  2. Walk the rooms it serves and unplug every appliance, lamp, charger, space heater, and tool on that circuit
  3. Try resetting again

If the breaker holds with everything unplugged, the cause is on the load side — something you plugged in is the problem. Plug things back in one at a time, leaving each on for a few minutes. Whatever causes the trip is the culprit.

If the breaker trips even with everything unplugged, the cause is on the wiring side — a problem in the circuit itself, not the loads. That’s where we come in.

Step 4: Is it an overload? (the most common cause)

The most common reason a breaker trips: too much load on the circuit. A 15-amp breaker is rated for a sustained 12 amps (80% of capacity). A 20-amp breaker is rated for 16 amps sustained.

Common scenarios that overload circuits:

  • Space heater + microwave on the same kitchen circuit. Space heaters draw 12.5 amps on their own. Add anything else and you’re over.
  • Hair dryer + curling iron on a bathroom GFCI. Some hair dryers pull 15 amps by themselves.
  • Holiday string lights + a few accent lamps on a bedroom circuit. LED strings are fine; older incandescent strings draw real current.
  • Window AC unit on a circuit shared with other rooms. Window ACs need their own dedicated circuit, period. If the breaker serving your AC keeps tripping, the problem may be the compressor rather than the circuit — Climate Pros SD can diagnose the equipment side while we check the wiring.

If you can identify an overload, the fix is to redistribute loads. If you can’t avoid the overload (e.g., your bathroom GFCI just won’t hold a hair dryer), you need a dedicated 20-amp circuit added — that’s a real electrical job.

Step 5: Could it be a short circuit or ground fault?

If the breaker trips immediately when you plug in a specific device, that device has a short circuit or ground fault. Common culprits:

  • Old extension cords with damaged insulation
  • Lamps with frayed cords at the base
  • Power strips that have been overheated
  • Appliances with internal motor or heating element shorts (toasters and coffee makers are common)

Stop using the device and replace it. If the device is expensive (a refrigerator, a washing machine), have it diagnosed by an appliance repair tech rather than throwing it out.

Electrician using a digital clamp meter to read the current draw on a single hot conductor inside an open electrical panel
If a breaker trips repeatedly under normal use, a clamp meter shows whether it’s a real overload or a failing breaker. Photo: Bright Pro Electric.

Step 6: Is your AFCI breaker nuisance-tripping?

If your home was built or rewired after 2014, many of your circuits are protected by AFCI breakers (Arc Fault Circuit Interrupters). AFCIs are designed to detect arcing — the kind of sparking that happens at a damaged wire connection — and trip before a fire can start.

The problem: AFCIs sometimes trip on what’s called a “nuisance trip” from electronic noise that mimics arcing. The most common offenders:

  • Older treadmills and exercise equipment
  • Some vacuum cleaners (especially older bagless models)
  • Certain LED bulbs from cheap manufacturers
  • Window AC units with worn capacitors
  • Some space heaters

If your AFCI trips with a specific device but holds otherwise, don’t disable the AFCI. AFCIs catch real arc faults, and replacing one with a non-AFCI breaker leaves you exposed. The fix is to replace the device, or to have an electrician test the AFCI for genuine vs. nuisance trip behavior.

What if the breaker itself is failing?

Breakers wear out. After 20–30 years of use (or after a major fault event), the internal mechanism can weaken. A worn breaker trips at lower current than it’s rated for, or fails to trip when it should.

We test breakers with a clamp meter under load. If the breaker trips at 12 amps when it’s rated for 20 amps, the breaker is the problem and we replace it. Single-breaker replacement is a common, fast service call — usually $185 to $325 depending on breaker type and panel.

When should you stop troubleshooting and call?

Call us if:

  • The breaker trips with everything unplugged on the circuit (wiring problem)
  • You can’t identify which device is causing the trip after isolation
  • The same breaker trips on multiple unrelated devices (likely a loose neutral or bus connection)
  • An AFCI trips repeatedly with no clear source
  • You see any of the safety signs at the top of this article

A diagnostic call is $89, credited to the repair. Most repairs finish in the same visit.

Frequently asked questions

Is it safe to keep resetting a tripping breaker?

No. If a breaker trips more than twice in a row, stop resetting it. Forcing repeated resets on a tripping breaker can overheat the wiring, melt insulation, or cause arcing inside the wall. Diagnose the cause first.

How much does it cost to replace a bad breaker?

Single-breaker replacement is a common, fast service call — typically $185 to $325 depending on breaker type and panel. The diagnostic fee ($89) is credited toward the repair if we do the work.

What’s the difference between a tripped breaker and a bad breaker?

A tripped breaker reset normally and holds until another overload occurs. A bad breaker trips at lower current than its rating (e.g., tripping at 12 amps when rated for 20) or fails to reset cleanly. We test with a clamp meter under load to tell the difference.

Can a space heater trip a 15-amp breaker?

Yes. Most space heaters draw 12.5 amps on their own — that’s already at 83% of a 15-amp breaker’s capacity. Add anything else on the same circuit and you’re over the 12-amp sustained limit. Space heaters should run on a dedicated circuit.

If tripping breakers are a recurring pattern, the panel itself may need attention. Our panel upgrade cost guide covers pricing, timeline, and when a 200-amp upgrade makes sense. A burning smell alongside repeated trips is a different level of urgency — see our electrical burning smell emergency guide for what to do immediately. If your area is prone to PSPS shutoffs, our generator and backup power guide covers whole-home vs. portable options. And for a broader look at what electrical repairs cost in San Diego, check our electrician pricing guide.

See our full electrical troubleshooting service page or call (858) 400-8901.

Service across San Diego County — same-day on most weekdays from coastal communities through the mountain backcountry.