EZSMART Corporation, ESA/ECRA #7012690 , North York , Ontario
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A 15-amp breaker keeps tripping, and the fix looks obvious — swap it for a 20-amp breaker and the tripping stops. That single move is one of the most common and most dangerous DIY fixes in Ontario homes, and it is the reason for a real percentage of house fires investigated by the Ontario Fire Marshal each year. This guide explains whether you can replace a 15-amp breaker with a 20-amp breaker, why the Ontario Electrical Safety Code forbids it in most cases, and what to actually do about repeat tripping.
Direct answer: no, you cannot safely replace a 15-amp breaker with a 20-amp breaker on a branch circuit wired with 14 AWG copper conductor. The breaker rating exists to protect the wire, not the appliance. 14 AWG copper is rated for 15 amps continuous. Feeding it 20 amps overheats the insulation, damages the conductor, and creates a real fire risk inside the wall where you cannot see it.
Direct answer: a breaker is a self-resetting fuse for one job — disconnecting the circuit before the conductor gets hot enough to damage its insulation. Every conductor gauge has a specific ampacity rating in the Ontario Electrical Safety Code. 14 AWG = 15 amps. 12 AWG = 20 amps. 10 AWG = 30 amps. Sizing the breaker higher than the conductor’s ampacity means the wire runs hotter than its insulation is designed for.
Rule 14-104 of the OESC states that overcurrent protection must not exceed the ampacity of the conductor being protected. A 20-amp breaker on 14 AWG wire violates this rule unambiguously, and any home inspection or ESA inspection will flag it. If the appliance downstream keeps drawing 18 amps, the breaker upsize hides the load problem while the wire slowly cooks toward a fire.
Direct answer: if every conductor on the circuit is 12 AWG or larger — including any pigtails, extensions, and downstream connections — a 20-amp breaker is code-compliant. This is unusual in older Ontario residential branch circuits but occasionally happens when a kitchen counter circuit or garage circuit was over-built years ago.
Even in that case, the swap should include an inspection of every device on the circuit to confirm each receptacle and switch is rated for 20 A, plus an ESA notification because you are changing the branch’s overcurrent protection. Do not eyeball this — have a licensed electrician verify the gauge at every accessible point.
Direct answer: a 15-amp breaker that trips repeatedly is telling you one of three things — (1) the circuit is genuinely overloaded, (2) a specific appliance on the circuit has a fault, or (3) the breaker itself is worn out and tripping below its rated 15 amps. All three have safe fixes; none of them is “install a bigger breaker.”
Our post on telling if your panel is overloaded covers the whole-house overload signs. For a specific circuit that trips only in one room, our related post on GFCI outlets tripping walks through the appliance-fault diagnostic.
Direct answer: when a circuit is genuinely overloaded, the fix is either a new dedicated 15 or 20 amp circuit for the high-draw appliance, or moving one appliance to a different existing circuit. Both are permit-required in Ontario and both cost less than the fire investigation that follows an incorrectly-sized breaker.
Typical GTA cost for a new dedicated 20-amp branch circuit is $350-750 depending on how far the panel is from the new outlet and whether the wall is finished. That is a real cost, but so is the insurance denial that follows a house fire on an oversized breaker. The Electrical Safety Authority lists mismatched overcurrent protection and conductor sizing among the recurring residential incident categories in its annual Ontario Electrical Safety Report. Not a corner to cut.
In our experience investigating repeat-tripping breakers across the GTA, the fastest legitimate solution is almost never a breaker change — it is figuring out which appliance owns the trip. We ask the homeowner to make a note over the next week of what was running when the breaker tripped. Nine times out of ten a pattern emerges immediately (“it trips when the microwave and kettle run together,” “it trips only when the space heater is on”). Once we know the offending load, we either move it to a different circuit or add a dedicated one. Homeowners who reach for a 20-amp breaker instead almost always regret it — either from a scorched receptacle, an insurance issue, or a failed home inspection at resale.
Breaker keeps tripping and you are tempted to swap it? Book an ESA-certified electrician to diagnose the actual cause and add a proper circuit instead. Call us at 416-838-9006 or visit our contact page — we will get back to you the same day.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp
