Why does my fuse box keep tripping?
A tripping fuse box is annoying — but it's also your electrics protecting you. Here's what's usually behind it, how to safely track down the cause yourself, and when it's time to call an electrician.
The short answer
When a switch in your fuse box (consumer unit) keeps flicking off, it's doing exactly what it's designed to do: cutting the power the instant it senses something wrong. So a "tripping" board is rarely the problem itself — it's the messenger. Nine times out of ten the real cause is one of these:
- A faulty appliance — a kettle, washing machine, fridge or charger with a fault.
- An overloaded circuit — too much drawing power at once, often through extension leads.
- Water getting in — into an outdoor socket, a bathroom fitting, or a light after a roof leak.
- A damaged cable — a nail or screw through a wire, or rodent damage in the loft.
First, what's actually tripping?
Open your consumer unit and look at which switch has moved to the "off" position:
- A MCB (a single narrow breaker) trips on an overload or short circuit — usually one specific circuit, like the kitchen sockets.
- An RCD (a wider switch with a "T" or "test" button) trips on an earth fault — often water or a faulty appliance leaking current to earth. On older boards one RCD can cover several circuits, which is why the whole house can go dark.
- An RCBO combines both in one device, so only the affected circuit goes off.
Knowing which one tripped tells you a lot about what to look for next.
How to find the culprit (safely)
You can often pin down the cause yourself in a few minutes, without any tools:
- 1. Unplug everything on the affected circuit and switch off the lights it feeds.
- 2. Reset the breaker by switching it firmly back on. If it now stays on, the fault is in something you unplugged.
- 3. Reconnect one item at a time, waiting a moment after each. When it trips again, the last appliance you switched on is the likely culprit — stop using it and get it checked or replaced.
- 4. If it trips with nothing plugged in, the fault is in the wiring or an accessory itself. That's where an electrician comes in.
One important rule: if a breaker won't reset, don't keep forcing it. It's holding the power off for a reason.
When to call an electrician
Some situations need a professional rather than a process of elimination. Call us if:
- The board trips repeatedly or at random, with no obvious appliance to blame.
- It trips with everything unplugged — that points to a wiring or accessory fault.
- There's a burning smell, scorch marks, buzzing or sparks — switch it off and call straight away.
- You've an older board with rewireable fuses or a single RCD that takes out the whole house.
Our fault finding service uses a methodical, test-led process to isolate the exact cause rather than guessing — and many faults are traced and fixed in a single visit. If the board itself is past its best, a modern consumer unit with individual RCBO protection means a fault on one circuit no longer blacks out the whole house.
A quick safety note
Resetting a breaker and unplugging appliances is perfectly safe. Opening up sockets, light fittings or the consumer unit is not — that's live-working territory and should be left to a qualified electrician. If in doubt, leave it off and pick up the phone.
Get it sorted
If your electrics keep tripping and you're in Essex or East London, call 07912 284977 or get a free estimate. We'll find the fault, explain it in plain English, and put it right.