Why does my breaker keep tripping?

A breaker that trips once is doing its job. A breaker that trips every Sunday when the vacuum runs, or every January when the space heater comes out, is telling you something specific. There are three things it can be telling you, and what was running when it tripped usually points to one of them.

Is it overload, a fault, or a tired breaker?

Overload means the circuit is carrying more than its rating. A 15-amp bedroom circuit in a 1960s ranch off Farrell Road was drawn for a lamp, a clock and a radio. Put a 1,500-watt space heater on it with a hair dryer down the hall and it will trip, correctly, every time. The tell is timing: it trips when a particular thing runs, and it resets and holds until that thing runs again.

A fault is a short or a ground fault somewhere on the run: a nail through a wire in a finished basement, a failed splice in a box, water in an outside receptacle, a cord chewed behind the dryer. The tell is that the breaker trips the instant you reset it, or trips with nothing plugged in.

A worn breaker has been switching the same load for thirty or forty years and the trip mechanism has softened. The tell is a breaker that trips at loads it used to carry, and the electrician confirms it by finding it running warm or loose on the bus. Zinsco and Federal Pacific panels do the opposite and fail to trip, which is its own problem and the usual case for a same-amperage panel replacement.

How does an electrician test a breaker that keeps tripping?

The part worth doing before the visit is noting what was running when it tripped, and roughly when. Write it down; the electrician will ask. The testing happens at the panel and along the run, with the meters, and it goes in about this order:

1. A clamp meter on the circuit while the usual loads run. A reading near the breaker’s rating with the space heater on is overload, and it settles the question without opening a wall.
2. With the loads disconnected, the run gets tested for a short or a ground fault. If it trips with nothing on it, the electrician traces it box by box until the bad splice or the wet receptacle turns up.
3. Every GFCI upstream of the trouble gets found and checked. In a lot of the 1990s two-stories east of the canal one GFCI in the garage protects the outside outlets, and a wet October week trips it.
4. After the circuit has carried load, the breaker and its connection get a heat read and a check that the breaker still seats firmly on the bus. Warm is normal in July. Hot is not.

When it stops being a reset-and-forget

Stop resetting and call if the breaker trips immediately every time, if there is any smell at the panel, if the tripping circuit feeds the furnace or the sump pump, or if it is a Federal Pacific or Zinsco panel. Resetting a breaker into a real fault a dozen times is how a splice in a wall becomes a scorched box.

What the fix usually is

Overload gets a dedicated circuit for the load that keeps causing it, or the load moves to another circuit. A fault gets traced with a tester and repaired at the box or the device where it lives. A worn breaker gets replaced, which is a short visit when the panel is a common brand and a longer conversation when it is not. If the house is on a 100-amp service and every circuit is doing double duty, the honest answer is the panel, not the breaker.

If it is tripping right now with the furnace off in January, that is an after-hours emergency call. Otherwise, the trip charge and the first hour of tracing are listed with what a repair visit costs by the hour, and the electrician will tell you which of the three it is before quoting the fix.