Losing power is one of those things that’s obvious the moment it happens and genuinely confusing straight afterwards. Is it just your house, or the whole street? Is it something you did, or something that was already wrong? A few common causes explain most cases.
A regional power cut. Before assuming anything’s wrong with your wiring, it’s worth checking whether neighbouring houses have lost power too. This points to an issue with the wider supply rather than anything inside the property, and it’s usually resolved by the network operator rather than an electrician.
A tripped RCD or circuit breaker. This is the most common cause of a localised outage. RCDs are designed to cut power quickly if they detect an imbalance in current — often caused by a faulty appliance, damp getting into an outdoor fitting, or a fault developing in the wiring itself. A single trip that resets and stays reset is often just the RCD doing its job. Repeated tripping means the underlying cause hasn’t gone away.
An overloaded circuit. Plugging too much into one circuit, particularly with older wiring that wasn’t designed for the number of appliances a modern household uses, can cause a breaker to trip as a protective measure. This is more likely in kitchens and home offices, where multiple high-draw appliances often end up on the same circuit.
A fault in a specific appliance. Sometimes the problem isn’t the house wiring at all — it’s a faulty appliance drawing excess current or developing an internal short. Unplugging recently used appliances one at a time and seeing whether the fault clears can sometimes narrow this down, though a genuinely faulty appliance should be checked rather than simply plugged back in.
Ageing or deteriorating wiring. In older properties, insulation around cables can degrade over time, particularly where wiring has been disturbed by other building work. This is a less immediate cause but a more serious one, since it tends to keep causing problems until it’s properly addressed rather than resolving itself.
A fault at the consumer unit itself. Less common, but consumer units do fail, particularly older units that have been in place for decades. Warmth, discolouration, or a persistent buzzing sound from the unit are signs worth taking seriously.
Working out which of these applies isn’t always straightforward from the outside, and that’s really the value an electrician brings — not just restoring power, but identifying why it went off in the first place so it doesn’t happen again a week later.
FAQs
How do I know if it’s a power cut or a fault in my house? Check whether neighbouring properties have also lost power. If they have, it’s likely a supply issue rather than something local to your wiring.
Why does my RCD keep tripping? Repeated tripping usually means there’s an ongoing fault somewhere on that circuit — often a specific appliance, damp in an outdoor fitting, or wiring that needs attention.
Can too many appliances on one circuit cause a power outage? Yes, particularly in older properties where a circuit wasn’t designed for today’s number of devices. This typically shows up as a breaker tripping under load.
Is a consumer unit fault dangerous? It can be. Warmth, discolouration, or unusual sounds from a consumer unit are worth having checked rather than left.
