Can a space heater cause an electrical fire?

Yes, space heaters are one of the leading causes of electrical fires in homes. They can cause fires through overloaded circuits, damaged cords, or when placed too close to combustible materials.

Space heaters draw significant electrical current - typically 12-15 amps for a 1500-watt unit. When plugged into circuits already carrying other loads, or into circuits with aging wiring, this can cause overheating and potential fire. The most dangerous scenario occurs when homeowners use extension cords or power bars with space heaters, creating additional connection points where heat can build up and ignite surrounding materials.

Common fire hazards with space heaters include:

• Overloaded circuits - plugging a 1500W heater into a 15-amp circuit already serving other devices


• Damaged extension cords - frayed or undersized cords can overheat and spark


• Poor placement - heaters too close to curtains, furniture, or bedding


• Old wiring - knob and tube or aluminum wiring in older Ottawa homes can't safely handle modern electrical loads


• Faulty outlets - loose connections create heat and potential arcing

In Ottawa's older neighborhoods, many homes still have knob and tube wiring or aluminum wiring from the 1960s-70s. These systems weren't designed for today's electrical demands. Running space heaters on these older systems significantly increases fire risk, especially when combined with blown-in insulation that can overheat the old wiring.

Safety guidelines for space heater use:

• Plug directly into wall outlets, never extension cords or power bars


• Ensure the circuit isn't overloaded (space heater should be the only major appliance on that circuit)


• Keep 3 feet of clearance from combustible materials


• Never leave unattended or run while sleeping


• Check that outlets aren't warm to the touch after use

When to call an electrician immediately:

• Outlets feel warm when heater is plugged in


• Lights dim when heater turns on


• Burning smell from outlets or walls


• Frequent breaker trips when using the heater


• Your home has knob and tube or aluminum wiring

If you're regularly using space heaters because your home's heating system is inadequate, consider having dedicated 20-amp circuits installed for heater use, or explore more permanent solutions like baseboard heaters or heat pumps. Under the Ontario Electrical Safety Code, any new circuits require ESA permits and professional installation.

For homes with older electrical systems, a panel upgrade and rewiring may be necessary to safely handle modern electrical loads. Electrical Ottawa can assess your home's electrical capacity and recommend safe solutions for your heating needs.