How to Prevent an Electrical Fire in Your Home

Electrical fires are the quiet category. There is no moment of carelessness to point at, no pan left on the stove, no candle knocked over.

They start inside walls, inside cords and inside panels, often after weeks of small warnings that looked like nothing.

Which is the good news. Most of those warnings are noticeable if you know what they are, and most of the fixes are cheap compared to the alternative.

If you are reading this because something already burned, the more urgent page is what to do first after a house fire. Come back to prevention once the house is stable.

How do you prevent an electrical fire at home?

You prevent an electrical fire by attacking three things: the load you put on circuits, the condition of the cords and devices, and the age of the wiring behind the walls.

Behavior handles the first two. Only an electrician handles the third, and that is the part homeowners skip.

Here is the whole thing in one list, roughly in order of how much risk each item removes.

1. Never ignore a breaker that trips repeatedly. A breaker doing its job twice is information. Resetting it a third time without finding the cause is the mistake.
2. Plug heat producing appliances directly into a wall outlet. Space heaters, irons, kettles, microwaves, toasters and window air conditioners, never onto a power strip or extension cord.
3. Treat extension cords as temporary. If a cord has been in place for more than a few weeks, that location needs a real outlet.
4. Replace damaged cords rather than repairing them. Cracked insulation, exposed conductors, a loose plug or a warm spot means the cord is finished.
5. Never run a cord under a rug, through a doorway or under furniture. Crushing and abrasion damage the insulation where you cannot see it.
6. Do not daisy chain power strips. One strip per outlet, and never a strip plugged into another strip.
7. Use the right bulb wattage for each fixture, and never put a higher wattage bulb in an enclosed fitting.
8. Keep three feet of clear space around every heater, and turn it off whenever you leave the room or go to bed.
9. Clean the dryer lint filter every load and have the vent duct cleaned annually.
10. Get an inspection if the home is more than about 40 years old, has aluminum branch wiring, or you have never had the panel looked at.

Notice what is not on that list. There is no gadget that fixes bad wiring, and no habit that compensates for a failing panel.

What are the warning signs of an electrical fire risk?

Almost every electrical fire announces itself first. The signs are subtle enough to live with, which is exactly why people do.

• A burning or fishy smell with no source you can find. Overheating plastic insulation smells acrid and slightly fishy, and it is the most urgent sign on this list.
• Warm or hot outlets and switch plates. Cover plates should be at room temperature. Warm means resistance, and resistance means heat.
• Discolored or scorched outlets. Brown or black marks around the slots mean arcing has already happened.
• Breakers that trip repeatedly on the same circuit, or fuses that keep blowing.
• Buzzing, sizzling or crackling from an outlet, switch or the panel itself.
• Flickering or dimming lights when an appliance starts, which points to a loose connection or an overloaded circuit.
• A mild shock or tingle when touching an appliance or a switch plate.
• Plugs that fall out of outlets. Loose contacts arc, and worn receptacles are cheap to replace.
• Sparks when plugging anything in. A brief small spark can be normal. A visible flash or repeated sparking is not.

Two of those are stop now signals rather than call soon signals. A burning smell and a scorched outlet mean switch off that circuit at the panel and get an electrician out.

The rest justify a call within days. None of them justify waiting to see whether it settles down.

How do cords, outlets and power strips start fires?

Through heat, and heat comes from two mechanisms: too much current through too little conductor, and arcing across a bad connection.

Overload is the obvious one. A cord rated for a lamp does not care that you plugged in a heater. It just warms up, softens, and eventually fails.

Arcing is the sneaky one. A loose screw terminal, a worn outlet contact or a cracked conductor creates a tiny gap, current jumps it, and the temperature at that point goes far higher than anything the breaker will notice.

That is the crucial detail. A standard breaker protects against overload and short circuit. It does not detect a small arcing fault that is quietly charring the inside of a wall box.

The rules that follow from this are boring and effective.

• One high draw appliance per outlet. Heaters, air conditioners, microwaves and space heaters get a wall outlet to themselves.
• Check the strip has a real breaker, not just a switch, and replace strips that have absorbed a surge event.
• Uncoil extension cords fully before use. A coiled cord under load traps its own heat.
• Match the cord to the job. A thin indoor cord on an outdoor tool or a heater is a common ignition point.
• Replace two prong outlets in rooms where you use grounded equipment, rather than defeating the ground pin with an adapter.
• Retire anything with a repaired plug. Tape is not insulation and a taped cord is a fire waiting for a warm day.

Arc fault circuit interrupters exist specifically for the arcing problem. They have been required by the National Electrical Code for many home circuits since 1999, which means most homes built before then have none.

Adding AFCI breakers or AFCI receptacles to older bedroom and living area circuits is one of the highest value upgrades available to an older house, and it is a straightforward job for an electrician.

Which wiring and panel problems do you need an electrician for?

The ones you cannot see, cannot smell, and cannot fix by being careful. These are the reason the dollar cost of electrical fires keeps climbing even as the number of fires stays roughly flat.

Get a licensed electrician to inspect if any of the following apply to your home.

• Aluminum branch circuit wiring, common in homes wired between roughly 1965 and 1973. Aluminum expands, contracts and oxidizes at terminations, which loosens connections and causes arcing. It is repairable with approved connectors, but it needs doing.
• Knob and tube wiring, found in homes built before about 1950. It has no ground, it degrades with age, and it overheats badly when buried in modern insulation.
• A 60 amp service or an old fuse box, which is undersized for how any modern household actually uses electricity.
• Panels with a documented failure history. Certain older brands are known in the trade for breakers that fail to trip, and an electrician can identify yours on sight.
• Oversized fuses or breakers. A 30 amp breaker protecting 15 amp wiring is a fire waiting for a load, and it is a surprisingly common find.
• Any DIY wiring you inherited from a previous owner, especially junction boxes without covers or splices outside a box.
• Recessed lights buried in insulation that are not rated for insulation contact.

A full home electrical inspection typically runs a few hundred dollars. Set that against what an electrical fire costs, and against what your insurer may argue about afterwards.

That argument is real and specific. Policies pay for the fire damage but commonly exclude the failed component itself, and old wiring can affect the claim in other ways too, which is covered in does homeowners insurance cover an electrical fire.

Which appliances cause the most electrical fires?

The ones that make heat, the ones that run unattended, and the ones with motors that get slowly choked with dust or lint.

• Portable space heaters. High draw, often on the wrong cord, often too close to something soft. They are the single most preventable item in the house.
• Clothes dryers. Lint is fuel and a blocked vent traps heat. Clean the filter every load and have the duct cleaned yearly.
• Dishwashers and washing machines. They combine water, heat and a motor, and they run while people sleep or leave the house.
• Refrigerators and freezers. Dust on the condenser coils makes the compressor work harder and hotter. Vacuum the coils twice a year.
• Microwaves and toaster ovens. High draw and frequently sharing a circuit with everything else on a kitchen counter.
• Lithium ion battery chargers. Charge e-bikes, scooters and tool batteries away from exits and never overnight while everyone sleeps.
• Extension cord powered anything in a garage or workshop, where cords get crushed, damp and forgotten.

The unattended rule is worth repeating on its own. Dishwashers, dryers and washing machines should run while someone is home and awake.

Kitchens carry the most fire risk of any room by a wide margin, though cooking rather than wiring drives most of it. The ranked causes are in the number one cause of kitchen fires.

What do you do if an electrical fire starts?

Get out first. Everything below applies only to a small fire you can reach safely with a clear exit behind you.

1. Cut the power if you can do it safely. Unplug the item, or switch off the breaker. Removing the electricity often stops the fire.
2. Never use water. Water conducts, and throwing it on an energized fire risks electrocution as well as spreading the fire.
3. Use a Class C rated extinguisher. A standard household ABC extinguisher is rated for electrical fires. Aim at the base, from about six feet.
4. Smother a very small contained fire with a fire blanket if you have one, and only if the power is off.
5. Leave and call 911 the moment the fire is larger than a wastebasket, or if it has reached a wall, ceiling or the panel.
6. Do not restore power to that circuit afterwards until an electrician has inspected it, even if the fire is completely out.

The water rule catches people out because the instinct is so strong. The physics behind why water is the wrong answer on other fire types too is in why you should never put water on a grease fire.

And if a fire did happen, however small, the recovery has an order that saves money. The order of operations after a house fire maps the whole sequence.

Do smoke alarms actually help with an electrical fire?

Yes, and more than people expect, because electrical fires often start in a place nobody is looking and smoulder for a long time before they break out.

The current guidance is straightforward and worth checking against your house tonight.

• One alarm inside every bedroom, one outside each sleeping area, and one on every level including the basement.
• Interconnected alarms so that when one sounds, all of them sound. This matters most for a fire starting in an unoccupied part of the house.
• Test monthly and replace batteries when the unit chirps, not when it becomes annoying enough to remove.
• Replace the whole alarm every 10 years from the date on the back, because the sensor degrades whether or not it has ever sounded.
• Add carbon monoxide alarms on every level if you have any fuel burning appliance or an attached garage.

One honest closing point. Perfect habits do not make an old panel safe, and a new panel does not make a taped up heater cord safe. You need both halves.

If you do the ten items in the first list and get one inspection, you have removed most of the risk that is actually available to remove in a home.

For the cooking side of home fire prevention, which is a bigger category again, how to prevent a kitchen grease fire covers the habits and setup that matter there.

Keep reading

InsuranceDoes Homeowners Insurance Cover an Electrical Fire?By CauseThe Number One Cause of Kitchen FiresPreventionHow to Prevent a Kitchen Grease FireBy CauseWhy You Should Never Put Water on a Grease FireEmergencyWhat to Do First After a House FirePreventionWhy You Should Never Leave the Stove Unattended