Fuse box keeps tripping? Here’s what it usually means
Guidance last checked on against UK safety regulation and the sources behind our service pages.
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 swap out a breaker, an RCD or the consumer unit yourself — replacing a consumer unit is notifiable work under Part P of the Building Regulations, so it has to be either self-certified by a scheme-registered electrician or signed off by building control
- Don't touch anything that smells hot, looks scorched, or crackles — switch the installation off at the main switch and book urgent help; if there's smoke or scorching you can see spreading, call 999 first
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. Check when the installation was last inspected, because the answer differs by tenure: if you rent, your landlord must have an Electrical Installation Condition Report (EICR) carried out at least every 5 years and give you a copy, and that has been a legal duty in the private rented sector in England since 2020. If you own the place there is no such law — every 10 years is the widely recommended interval. Either way, repeated tripping is the prompt.
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.