Lights out? How to tell if it's a power cut or your fuse box
When the lights go out, you might be dealing with one of two very different problems. A power cut means the electricity supply to your street or area has stopped, and you can't fix it at home. A tripped fuse box (also called a consumer unit) means something inside your home has cut the power, usually to protect you from a fault.
Knowing which one you're dealing with saves time and stress, and tells you who to call. At Go Assist, our electricians get this question a lot once the autumn storms arrive. Here's how to work it out in a few minutes.
Step 1: Look outside
Start by checking whether the problem is just your home.
- Are your neighbours' lights on?
- Are the street lights working?
- Is anyone on your road or local social media group mentioning a power cut?
If everything outside is dark too, it's almost certainly a power cut. Skip to What to do in a power cut below.
If everyone else has power and you don't, the problem is likely inside your home. Head to your fuse box.
Step 2: Check your fuse box
Your fuse box is usually in a hallway cupboard, under the stairs, in the garage, or near your front door. It's worth finding it now, while the lights are on.
Open the cover and look at the row of switches. In most modern homes, you'll see two types:
- RCDs (Residual Current Devices). Usually wider switches, often with a "T" or "Test" button. They protect you from electric shocks by cutting power when they detect a fault.
- MCBs (Miniature Circuit Breakers). Smaller switches, each controlling one circuit, such as the downstairs lights, upstairs sockets or the cooker.
If any switch is pointing down (or in the opposite position to the others), it has tripped. That's your answer: it's not a power cut.
Older homes may have a fuse box with pull-out fuses rather than switches. If that's what you have, don't try to replace the fuse wire yourself. Call an electrician instead. It may also be worth having your fuse box checked or upgraded.
Step 3: Reset a tripped switch safely
Before you touch anything, check for warning signs. Don't touch the fuse box if:
- There's a burning smell
- You can see scorch marks, smoke, or melted plastic
- The fuse box or the area around it is wet
- Your hands are wet
If you notice any of these, leave it alone and call an emergency electrician.
If everything looks normal:
- Unplug appliances on the affected circuit. If you're not sure which ones, unplug the main suspects: kettle, toaster, washing machine, tumble dryer, dishwasher, and any outdoor lighting.
- Switch the tripped switch back up. If it was an RCD, you may also need to switch the MCBs below it off first, reset the RCD, then switch each MCB back on one at a time.
- Plug your appliances back in one at a time. If the switch trips again when a particular appliance goes back in, you've likely found the culprit.
If the switch won't stay up even with everything unplugged, the fault is probably in the wiring rather than an appliance. That's a job for a qualified electrician.
Why does my fuse box keep tripping?
A one-off trip isn't usually anything to worry about. But if it keeps happening, it's your electrics telling you something's wrong. Common causes include:
- A faulty appliance. Worn heating elements in kettles, ovens, washing machines and tumble dryers are frequent offenders.
- Too much on one circuit. Running several high-power appliances from the same set of sockets can overload it.
- Water getting in. Outdoor lights and sockets, or leaks near electrical fittings, are common triggers in wet and stormy weather.
- Damaged or ageing wiring. Loose connections, damaged cables, or a circuit that wasn't installed correctly.
Our electricians can trace the fault for you with our electrical fault-finding service. Repeated tripping is one problem you shouldn't leave to sort itself out. Plus, if the problem turns out to be a faulty appliance, our appliance repair experts are on hand to help too.
What to do in a power cut
If the whole street is out, the fault is with the local network rather than your home. Here's what to do:
- Call 105. It's the free national power cut helpline, and it puts you through to your local network operator, the company that looks after the power lines and substations in your area (not your energy supplier). They can tell you what's happened and when power is expected back. In Northern Ireland, call NIE Networks on 03457 643 643.
- Switch off appliances at the wall, especially ones that heat up, such as ovens, hobs, irons and heaters. This stops them coming back on unattended when the power returns.
- Leave one light switched on so you know when the power's back.
- Keep your fridge and freezer doors closed. A full freezer will usually stay frozen for around 48 hours if the door stays shut, and a half-full one for around 24 hours.
- Use torches, not candles, wherever you can.
- Check on vulnerable neighbours, especially older people or anyone who relies on medical equipment.
If someone in your household is elderly, has a disability or relies on powered medical equipment, you can sign up to your network operator's free Priority Services Register. They'll keep you updated during power cuts and offer extra support.
When the power comes back on
Once the power returns, switch your appliances back on gradually rather than all at once. Check your fridge freezer is cooling properly, and reset any clocks or timers on your oven and boiler.
If an appliance won't start, or your fuse box trips as soon as the power returns, there may be a fault that needs looking at.
Need an electrician?
Whether your fuse box keeps tripping, a switch won't reset, or you've spotted signs of damage, our qualified electricians can find the fault and fix it, often the same day or the next. Book online in a couple of minutes or call us on 0333 733 1234.
