Circuit breaker keeps tripping: causes, safe checks and when to stop

Every competing page says "too many appliances" and stops. The arithmetic is more useful than the phrase, and it usually settles the question in one line.

A 15 amp circuit at 120 volts carries 1,800 watts at absolute maximum, and 1,440 watts for anything running more than three hours. A single 1,500 watt space heater therefore occupies the whole circuit before you have plugged in anything else.

Add a kettle, a microwave or a hair dryer to that and the total passes the rating within seconds. If your circuit breaker keeps tripping only when two specific appliances run together, you have an overload rather than a fault, and the fix is redistributing the load rather than calling anyone.

How many resets is too many

The reason this matters more than it sounds is that arc faults are quiet. ESFI attributes more than 28,000 home fires a year and over $700 million in property damage to arcing faults, and an arcing connection behind drywall gives no smell, no sound and no visible symptom until it ignites something.

The rule worth adopting: once the circuit is empty and it still trips, the breaker has stopped being a nuisance and started being the only thing standing between a fault and a fire. Leave it off.

Tripping with nothing plugged in

This is the single most useful diagnostic result you can get, because it eliminates the entire category of appliance faults in one step.

What is left is fixed: cable inside a wall or ceiling, a hardwired device such as a light fitting, an extractor fan or a doorbell transformer, a damaged junction, or the breaker itself. Remember that hardwired loads count as connected even when nothing is plugged in, so switch off every light and fan on that circuit before concluding it is truly empty.

Once it genuinely trips on an empty circuit, there is no safe homeowner step remaining. Testing that fault means opening the panel and metering the circuit, which is licensed work.

AFCI and GFCI breakers trip for different reasons

The highest-ranking commercial page for this search discusses short circuits and never mentions arc-fault protection at all, which leaves a large share of modern tripping unexplained.

• GFCI devices trip on current leaking to earth, often only a few milliamps. They protect people rather than wiring, and they are required in kitchens, bathrooms, garages, basements and outdoors.
• AFCI breakers trip on the electrical signature of an arc rather than on current. They exist specifically to catch the arcing faults ESFI links to 28,000 fires a year.
• Both nuisance-trip on some motor loads and older appliances, which is a genuine annoyance and still not a reason to downgrade them.
• Never replace either with a standard breaker to stop the tripping. That silences the detector rather than fixing the fault, and it fails inspection.

What tripping tells you, appliance by appliance

Once you have identified the device, the pattern narrows the cause further. These are typical patterns rather than diagnoses, and each one ends with the same advice.

1. Air conditioner or heat pump. Trips on start-up point at inrush current or a failing start capacitor. Trips after running a while point at a compressor drawing high.
2. Clothes dryer. Usually a heating element that has sagged and is shorting to the drum housing. A dryer that trips and smells hot is a fire risk, not an inconvenience.
3. Microwave. Often not the microwave at all but a shared kitchen circuit. Where it genuinely is the unit, a failing magnetron draws hard as it heats.
4. Refrigerator. Compressor start current, or a defrost heater that has failed short. Refrigerators are also the classic cause of a GFCI nuisance trip in a garage.

The dryer case deserves particular attention because it combines an electrical fault with a lint load. The US Fire Administration publishes guidance on clothes dryer fire safety for exactly this reason.

Intermittent faults cost more to find than constant ones, because the electrician has to provoke the condition before they can measure it. Budget two hours rather than one on anything that only trips occasionally. Full rate detail sits in our guide to what an emergency electrician charges.

How the matching works, and what we do not do

Emergency Services 24H is a referral service. We do not employ electricians and we do not carry out electrical work.

Your request routes by ZIP code to licensed, insured contractors covering your area, and they contact you directly. Tell them whether the circuit trips empty, because that single fact changes what they bring.