Fuse box keeps tripping? Here’s what it usually means
A consumer unit that trips repeatedly is protecting you from a real fault: usually a failing appliance, moisture in a fitting (bathroom fans and outside sockets are prime suspects), an overloaded circuit, or a deteriorating cable. The pattern tells the story — what trips, when, and what's plugged in.
Likely causes
- A faulty appliance
- The classic. Unplug everything on the affected circuit, reset, and reintroduce one at a time. Kettles, washing machines and cheap chargers are frequent offenders.
- Moisture ingress
- Trips after rain or showers point to water in an outdoor socket, garden lighting, or a bathroom fan. Leave that circuit off until it's inspected.
- Overload
- Heaters and high-draw appliances sharing one circuit will trip it under load — a symptom worth an electrician's opinion on your circuit layout.
- Failing wiring or accessory
- If it trips with nothing plugged in, the fault is in the fixed installation — cable damage, a failed accessory, or age. That needs professional fault-finding.
What not to do
- Don't hold or tape an RCD on — it's the only thing standing between a fault and a fire or shock
- Don't keep resetting a breaker that trips instantly: leave the circuit off
- Don't touch anything that smells hot, looks scorched, or crackles — switch off and book urgent help
When to request help
Same day if it trips instantly on reset, won't hold at all, or anything is scorched or burning-smelling. Otherwise book fault-finding promptly — nuisance tripping rarely improves on its own.
Related questions
Is repeated tripping dangerous?
The tripping itself is the safety system working. What's dangerous is the underlying fault — and the habit of resetting without investigating. If an EICR hasn't been done in 10+ years, this is the prompt.
Reviewed by the London Heroes Operations Team. General guidance, not a substitute for an on-site professional assessment — and never for the gas emergency line (0800 111 999) if you smell gas.