What is this?
A socket that sparks during normal use — not just during plug insertion — is experiencing electrical arcing. This means electricity is jumping across a gap between conductors rather than flowing through a solid connection. Arcing generates extreme temperatures (thousands of degrees) and is a leading cause of electrical fires. Under BS 7671, all socket connections must be mechanically secure and electrically sound. A sparking socket fails both requirements.
Common causes
- Severely worn internal socket contacts that cannot grip plug pins
- Loose terminal connections at the back of the socket creating intermittent contact
- Damaged or corroded socket internals
- Short circuit or tracking across the socket face from moisture or contamination
- Broken or cracked socket allowing movement in the connections
- Overloaded socket with connections degraded by sustained overheating
Is it dangerous?
Yes, this is dangerous. A sparking socket is actively arcing, which generates temperatures far exceeding the ignition point of wood, insulation, and other building materials. Arc fault fires can start behind the socket in the wall cavity where you cannot see them. Stop using the socket immediately, unplug everything, and turn off the circuit at the consumer unit.
Can I fix it myself?
No. Do not use the socket. Unplug everything from it and, if possible, turn off the circuit at the consumer unit. Do not attempt to open or repair the socket. If you see sparking from a socket that is not in use (nothing plugged in and switch off), this is especially serious — turn off the circuit immediately and call an emergency electrician.
When to call an electrician
Call an electrician urgently — within the same day if possible. If the socket sparks without anything plugged in, or if sparking is accompanied by smoke, burning smell, or visible damage, treat it as an emergency. Arc faults can smoulder behind walls for hours before becoming a visible fire.
What will an electrician do?
Isolate the circuit and remove the socket faceplate for inspection
Check for arc damage, carbon tracking, and overheated connections
Replace the socket with a new BS 1363 compliant outlet
Inspect and repair any damaged wiring in the back box
Test the ring circuit integrity (R1+R2, insulation resistance)
Recommend arc fault detection devices (AFDDs) for enhanced protection if appropriate
Typical cost
£70 – £180
Socket replacement and connection inspection is standard. If wiring damage from arcing requires cable replacement, costs are higher. AFDDs are an additional investment if recommended.
