Safety
Why your breaker keeps tripping, and when to call an electrician
A breaker that trips once is doing its job. One that keeps tripping is telling you something. Here's how to read it, what you can check yourself, and when to stop and call.
What a tripping breaker is telling you
A breaker is a switch that watches the current on one circuit. When the current climbs past what the wire behind it can safely carry, or leaks somewhere it shouldn't, the breaker opens. The lights go out, but the wire stays cool.
So a trip means the protection worked. The real question is why it had to. One trip while the kettle and toaster run together is a hint. A breaker that keeps tripping is a pattern, and patterns have causes worth finding.
Overload, short circuit, ground fault or a failing breaker
Nearly every repeat trip comes down to one of four things.
| Cause | How it usually behaves | Typical trigger |
|---|---|---|
| Overload | Trips after something has run for a while | Too many heating appliances on one circuit |
| Short circuit | Trips instantly, sometimes with a pop or flash | A damaged cord, a loose wire touching another, a failed appliance |
| Ground fault | Trips a GFCI device, often in damp places | Current leaking to ground through water or worn insulation |
| Failing breaker | Trips at loads it used to handle, or feels warm | Age, heat or a loose connection where the breaker meets the panel |
Timing tells them apart. Notice when it trips, what was running, and whether it waits or goes at once. Those three details narrow things down faster than anything else.
Why does my breaker trip when the microwave or space heater is on?
That's the classic overload. Most household outlet circuits are 15 amps at 120 volts. A typical 1,500-watt space heater draws about 12.5 amps on its own. Add a microwave, a kettle or a hair dryer on the same circuit, and the total passes what the breaker allows.
Space heaters are the worst offenders because they run for hours. Microwaves, air fryers and kettles run in short bursts, but they often sit side by side on one counter. In older Toronto houses, a single circuit may feed outlets in two or three rooms, so the overload isn't always obvious.
The fix is to spread the load or add circuits. A heater you rely on every winter deserves its own circuit, or a permanent heating solution. A kitchen that trips every week probably needs more counter circuits.
Why does a breaker trip immediately after reset?
If the breaker snaps off the moment you push it on, it isn't an overload. Overloads need time to build heat. An instant trip points to a short circuit or a ground fault somewhere on that circuit.
Unplug everything on it and try once more. If it holds now, the fault is probably in something you unplugged. Plug items back one at a time and the culprit usually shows itself. If it still trips instantly with nothing connected, the fault is in the wiring, a device or something hardwired. Leave it off and call.
Breaker keeps tripping with nothing plugged in
A circuit with nothing plugged in still has things on it. Ceiling lights, bathroom fans, baseboard heaters, a furnace or a garbage disposal may be wired in directly. Any of them can fail in a way that trips the breaker.
Once those are ruled out, the cause is in the circuit itself. A nail or screw driven through a cable during an old renovation is common. So is a loose splice in a junction box, a cracked outlet, or water reaching a box. Breakers also wear out, and a tired one can trip below its rating.
That's why a breaker that keeps tripping "for no reason" is worth a visit. There is a reason. It's just out of sight.
Breaker keeps tripping at night, when it rains or after a power outage
At night
Heaters, electric blankets and baseboards all work harder after dark in winter. A circuit that copes by day can overload overnight. In summer, an air conditioner cycling through the night can do the same.
When it rains
Water finds outdoor outlets with worn covers, exterior lights, cracked conduit and leaky basement walls. A circuit that trips only in wet weather usually has moisture reaching it, and that ground fault needs finding before the next storm.
After a power outage
When power returns, fridges, freezers, furnaces, sump pumps and air conditioners can all restart together. That brief rush can trip a breaker already near its limit. Once is a note; a regular habit points to an overloaded or failing circuit.
When the AC turns on
Compressors draw a burst of current as they start. A breaker that trips each time can mean a failing part in the unit, or a worn breaker. We check the circuit; an HVAC technician checks the unit.
Why does the breaker keep tripping in the basement?
Basements collect the circuits nobody planned. A freezer, a dehumidifier, a sump pump, a home gym and a workbench can all end up on one or two circuits. Finished basements often have outlets tapped off an old circuit rather than new runs from the panel.
Moisture is the other half of the story. Damp concrete, a leak near a box or condensation on cold pipes can cause ground faults that come and go with the weather. If the sump pump shares a circuit that keeps tripping, treat it as urgent. A pump that loses power during heavy rain can let the basement flood.
GFCI and AFCI tripping: what's different
Not every trip comes from an ordinary breaker. Many homes have devices that watch for specific dangers.
GFCI (ground fault)
It compares the current going out with the current coming back. If a little leaks away, through water or a person, it cuts power fast. You'll find them in bathrooms, kitchens, outdoors and many basements, as outlets with test and reset buttons or as breakers.
AFCI (arc fault)
It watches for the electrical signature of arcing, the kind a loose connection or a crushed cord produces. Newer homes and renovations have them on many circuits, usually as breakers in the panel.
Both trip on real faults, and both deserve to be taken seriously. Some older motors and appliances can also set them off without a dangerous fault. Telling a genuine fault from a nuisance trip takes testing, not guesswork.
One GFCI outlet can also protect other outlets further along its circuit. If a bathroom or garage outlet is dead, look for a tripped GFCI close by before assuming the worst.
Breaker won't reset? Here's why
A tripped breaker usually rests in a middle position. To reset it, push the handle firmly all the way to OFF first, then back to ON. Skipping the OFF step is the most common reason a reset seems to fail.
If it still won't stay on, something on the circuit is still faulted, or the breaker itself has failed. Don't hold the handle up, tape it or wedge it. That stops it protecting the wire. Leave it off and call an electrician.
A buzzing breaker or a warm panel
A breaker should be silent. A buzz, hum or crackle from the panel means current is struggling across a poor connection, or the breaker is failing inside. Heat is the next warning: a breaker or cover that's warm to the touch, a burnt smell, or brown marks around a breaker.
None of these is a wait-and-see problem. Don't open the cover, keep people away from the panel, and call for help.
What you can safely check yourself
A few checks need no tools and no opening of anything:
- Note what happened. What was running, what time it was, and whether the trip was instant or delayed.
- Unplug and switch off. Unplug everything on the dead circuit and turn off its lights and fans.
- Reset once. Push the breaker fully off, then on. Keep your hands dry and stand on a dry floor.
- Add things back slowly. Plug items in one at a time, a few minutes apart. If one trips it, you've found the problem appliance or the overload.
- Stop if it trips with nothing on. Leave the breaker off and book a visit.
Jot down which outlets and lights went dead as you go. That list saves time when we arrive.
What not to do
- Don't keep resetting it. Each reset onto a fault pushes current through whatever is damaged. One try is enough.
- Don't swap in a bigger breaker. A breaker is matched to its wire. A 20-amp breaker on wire sized for 15 amps lets that wire overheat inside the wall without tripping. It ends the nuisance and starts a fire risk.
- Don't run an extension cord from another circuit. It moves the overload; it doesn't fix it.
- Don't take the panel cover off. Parts behind it stay live even with the breakers off.
- Don't fit a used or mismatched breaker. Breakers are made for particular panels. One that clips in but isn't approved for that panel may not hold properly.
When a tripping breaker is an emergency
Call our 24/7 emergency electrician line straight away if a trip comes with any of these:
- A burning or hot plastic smell from an outlet, a fixture or the panel
- Smoke, sparks or scorch marks
- Buzzing or crackling from the panel
- Water near the panel, an outlet or a light
- The main breaker tripping
- A sump pump, furnace or medical equipment circuit that won't stay on
If there's smoke or flame, get everyone out and call 911 first. If wires are down outside, stay well back and call your utility.
When the real answer is more circuits or a bigger panel
If breakers trip because the house is asked for more than it was built to give, no repair changes that. Many older Toronto homes were wired before central air, induction ranges, home offices and electric cars. Their circuits, and sometimes their whole service, are too small for how people live now.
Sometimes one dedicated circuit for the heater, microwave or freezer solves it. If the panel has no room left, or the service is 60 or 100 amps, a panel upgrade may be the better long-term step. A load calculation tells you which.
What happens on a troubleshooting visit
We start with your notes: which breaker, how often, and what was running. Then we test the circuit, the devices on it and the breaker to trace the fault. Once we know the cause, we explain it and give you the price before any repair begins.
Our troubleshooting and repairs service covers this work across the GTA. In North York, see our North York troubleshooting page. If something smells hot or sounds wrong right now, call (647) 930-2907, any hour.
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