What to do in the next five minutes
Take these in order. This section is the whole point of the page; everything after it is explanation you can read once you have done these.
- Smoke, flame, or a smell that is intensifying — everyone out, call 911, do not search for the source
- No smoke: switch off the breaker feeding that area if you can reach the panel safely. If you cannot tell which one, switch off the main
- Do NOT open the panel cover. Do NOT unscrew outlet or switch plates
- Do NOT keep switching the circuit back on to check whether the smell returns
- Unplug what you can reach safely on that circuit, without touching anything warm
- Call us. Say you can smell burning — it changes how the call is handled
One thing not on that list, deliberately: finding the source. It is the natural instinct and it is the wrong one here. The smell travels, the heat is often being made somewhere other than where it smells strongest, and the places you would look — inside a panel, behind a cover plate — are the places where looking can hurt you.
Why the smell stopping is not good news
This is the part most worth understanding, because it is the reason people wait months and then have a fire.
Electrical overheating is nearly always caused by resistance at a connection — a terminal screw that was never fully tightened, a backstabbed outlet, a corroded joint, a breaker that no longer clamps its bus properly. Resistance turns current into heat. Heat degrades the connection: metal oxidises, plastic softens, contact area shrinks. A smaller contact area means MORE resistance, which means more heat next time. The process feeds itself, and it does so slowly enough that nothing appears to be happening between episodes.
So when the smell goes away, what has usually happened is that the load switched off — the heater cycled, the dryer finished, someone stopped using the room. The connection has not repaired itself. It is measurably worse than it was before the episode, and the next one starts from that worse position. “It only did it once” and “it stopped on its own” are the two sentences we hear most often about connections that later turn out to be badly damaged.
What the different smells usually mean
People describe electrical burning fairly consistently, and the descriptions are diagnostically useful.
- A sharp FISHY or urine-like smell — characteristic of overheating thermoset plastics, the material older outlets, switches and breaker bodies are moulded from. This one is strongly associated with a device or connection running hot
- A clean, sharp, SWIMMING-POOL smell — ozone, produced by arcing. Arcing makes relatively little current, so a standard breaker may never react to it, which is what AFCI protection exists to catch
- ACRID melting plastic — modern cable insulation or a cord, often an extension lead or a plug under a rug or furniture leg
- Hot DUST, metallic, appearing the first time a heater or heat pump runs in months — usually harmless dust burning off the elements, and it should clear within an hour
- A new appliance smelling for its first few hours of use — normally off-gassing, not a fault
The last two are the common false alarms and it is fine to be relieved by them. Everything above them is worth acting on the same day.
Where it tends to come from
In rough order of how often we find it: an OUTLET, particularly one feeding a heavy load like a heater, a window air conditioner or a kettle, and particularly a backstabbed one where the wire is held by a spring clip rather than a screw. A SWITCH, especially a dimmer working beyond its rating. A LIGHT FIXTURE, often one fitted with bulbs above its rated wattage years ago. An APPLIANCE or its cord, which is the one case where the wiring is not at fault. And the PANEL itself, which is the most serious because those connections feed everything.
A smell at the panel deserves separating out. It means heat at connections carrying far more current than any single circuit does. Switch off the main if you can reach it safely, do not open the cover, and call. If the cover is warm to the touch or there is any smoke, call 911 first — a panel fire is not something to be in the room with.
If your panel is a Federal Pacific or a Zinsco
Mention it when you call. Both brands have documented failure modes involving connections that overheat and breakers that do not trip when they should, and a burning smell in one of those panels is a different conversation from a burning smell in a modern one. We have separate guides on both, but do not stop to read them now — make the call first.