How to Reset a Tripped Breaker Once

Why this matters

A breaker trips to protect the wiring in your walls. Most of the time the reason is ordinary: too many things running on one circuit at once, and one reset after unplugging something fixes it. Some of the time the reason is a damaged cord, a failing appliance or a problem inside a wall, and in those cases a breaker that keeps tripping is the only thing standing between that problem and a fire. That is why this card has "once" in its title. One reset tells you something useful. A second, third and fourth reset just forces electricity through whatever the breaker was trying to stop.

Before anything else: if the panel or the breaker is hot to the touch, buzzing, crackling, smells burnt, shows scorch marks, or there is water on the floor in front of it, do not touch it. Leave the breaker off. If there is smoke or fire, get out and call 911; otherwise call an electrician, or the electric utility if you cannot safely get away from the panel's area.

What the handle positions look like

A tripped breaker does not always look obviously different from its neighbors. On most panels, ON points toward the center of the panel and OFF toward the outer edge.

 panel center                          panel edge
 (ON side)                             (OFF side)

 ON:       [###]----------------------
           handle all the way toward center

 TRIPPED:  -----------[###]-----------
           handle stopped partway, out of line
           with its neighbors; some breakers
           also show a colored flag in a window

 OFF:      ----------------------[###]
           handle all the way toward edge

 RESET:    TRIPPED -> push firmly to OFF (click)
                   -> then firmly to ON  (click)

Run your eye down each column looking for the one handle that is not lined up with the rest. On some panels the tripped handle sits only slightly short of ON and is easier to feel than to see when you move it: a tripped breaker moves toward OFF with little resistance.

Why a breaker trips: three causes, three meanings

• Overload. More current is flowing than the circuit is rated for, usually because several high-draw things are running at once. The breaker heats inside and trips after a delay that can run from seconds to a few minutes, depending on how far over the rating the load is. Unplug something and the cause is gone.
• Short circuit. Current found a shortcut it should not have, through damaged insulation or a failed appliance. The breaker trips instantly, often with a pop. The cause is still there after the reset.
• Ground fault or arc fault. Some breakers have a TEST button on the handle: these are GFCI or AFCI breakers, which trip on leaking current or on the electrical signature of arcing, such as a nail through a cable or a crushed cord. The cause is usually still there too. The tech-facing detail lives in GFCI and AFCI Troubleshooting Reference.

Only the first one is fixed by unplugging. One reset is how you find out which one you have.

Step 1: Turn off or unplug what was running

Before you go to the panel, turn off or unplug the things that were running on the dead outlets and lights, starting with whatever was on when the power went: a space heater, a hair dryer, a vacuum, a window air conditioner, a microwave.

Why: if it was an overload, resetting with the same load still connected trips it again, and you would wrongly conclude something is broken. With the load off, a reset that holds tells you the circuit itself is probably fine.

What breaks if you skip it: a short-circuited appliance still plugged in puts the full fault through the reset, which is the one moment you most want to avoid.

Step 2: Check the panel before you touch it

Dry floor, dry hands, nothing hot, buzzing or burnt. Stand to the side of the panel and use only the handle, the same stance as when you turn power off (see related: How to Shut Off Power at Your Electrical Panel).

Step 3: Push the handle fully OFF, then ON

Push the tripped handle firmly all the way to OFF. You should feel a click as the inside latches back into place. Then push it firmly all the way to ON.

Why: a tripped breaker cannot be pushed straight back to ON from the middle position; its internal latch has to be reset by going fully to OFF first. Pushing from the middle toward ON usually does nothing, and people then assume the breaker is broken.

Step 4: Read what happens next

• It holds. Check that the lights and outlets that went dead work again. Then plug things back in one at a time, waiting a minute between each, and leave out the combination that was running when it tripped.
• It trips again immediately, with everything unplugged. Stop. Leave it OFF. That is not an overload, because there is no load. Call an electrician.
• It holds, then trips again when one item goes back in. That item is the likely cause. Leave it unplugged and get it checked or replaced.
• It will not stay in the ON position at all. Leave it off and call an electrician.

Step 5: Reset only once

If the breaker trips again for any reason you cannot explain with simple arithmetic (below), you are done resetting. Leave it off, write down what was running and when it tripped, and call an electrician. See related: Your House Records File and What Goes In It.

Why repeated resetting hides a real fault: each reset into a short circuit or an arc sends a burst of current through whatever is damaged: a melted spot in a cord, a loose connection heating up inside an outlet box, a cable a nail went through. The breaker cuts it off each time, but each burst can worsen the damage, and a loose connection can heat up between trips without tripping anything. Breakers also wear with repeated faults. A breaker that keeps tripping is telling you the same thing louder each time; resetting it turns the warning off without touching the problem.

Worked example: the space heater, twice

The circuit: an upstairs bedroom on a 15-amp breaker (the number printed on its handle), feeding the bedroom outlets and the hall outlet outside it. A space heater's label reads 1,500 watts. A vacuum's label reads 10 amps.

The arithmetic you can do yourself. For anything with an ordinary household plug, amps are watts divided by 120. So the heater draws 1,500 divided by 120, which is 12.5 amps.

Thursday, 7 p.m. With the heater running, someone vacuums the hall using the outlet just outside the bedroom. About a minute later the bedroom and hall go dark.

• Step 1. The vacuum and the heater are unplugged.
• Step 2. The panel in the basement is dry, cool and quiet.
• Step 3. The bedroom breaker sits partway, out of line. Pushed to OFF it clicks, pushed to ON it clicks and stays.
• Step 4. It holds with nothing plugged in. The arithmetic explains the trip: 12.5 amps for the heater plus 10 amps for the vacuum is 22.5 amps, on a 15-amp breaker. That is 1.5 times the rating, which is a plain overload, and the short delay before it tripped fits one.

The heater goes back in alone and holds. The vacuum gets used on a downstairs outlet from now on. Space heater instructions usually ask that the heater be plugged straight into a wall outlet, and many warn against running other loads on the same circuit; this is why.

The following Tuesday, 6 a.m. The same breaker trips again. This time only the heater was running, and nothing else was on: no vacuum, no hair dryer.

The arithmetic no longer explains it. The heater alone is 12.5 amps, under the 15-amp rating. A trip with only a load that held fine last week is not an ordinary overload, so the rule in Step 5 applies: they do not reset it a second time to see what happens. The heater is unplugged and set aside, the breaker is left off, and an electrician is called.

What the electrician found: the outlet the heater was plugged into had a connection that had loosened and darkened from heat, which is common at outlets that carry a heater's current for hours every day. She replaced the outlet and checked the rest of the circuit.

What would have changed it:

• If the Thursday trip had happened instantly, with a pop, the moment the vacuum switched on, the delay that marks an overload would have been missing. That points to the vacuum, which would have stayed unplugged until checked.
• If the breaker had been warm or smelled burnt on Thursday, the before-anything-else rule would have applied and nobody would have reset it at all.

Reading the amp numbers in your own house

You can use the same arithmetic to plan around trips:

• Find the breaker size on the handle: usually 15 or 20 amps for outlets and lights. Kitchen counter circuits are commonly 20.
• Find the appliance's draw on its label, in amps, or in watts divided by 120.
• Add up what runs at the same time on that circuit. If the total is near or over the breaker's number, it will trip, and nothing is wrong except the plan.
• For something that runs for hours, such as a heater, electricians design circuits so that a load like that uses no more than 80 percent of the breaker's rating: 12 amps on a 15-amp circuit. A 12.5-amp heater on a 15-amp circuit is already past that, which is one more reason it should be alone on its circuit.

When the total is well under the rating and the breaker still trips, that is not something to plan around. That is Step 5.

When to call whom

• Electrician: a second unexplained trip, a trip with nothing plugged in, a breaker that will not stay on, any outlet or switch that is warm, discolored or smells hot, or a breaker that is hot, buzzing or burnt.
• 911: smoke, fire, or anyone shocked.

See related: When to Stop and Call a Licensed Pro Around the House.

References

• See related: GFCI and AFCI Troubleshooting Reference
• See related: Reading Your Electrical Panel and Its Breakers
• See related: How to Shut Off Power at Your Electrical Panel
• See related: How to Reset a Tripped GFCI Outlet
• Space heater and appliance manufacturers' instructions, which state the draw and how each must be plugged in