What is the difference between an RCD and an MCB? +
An MCB (Miniature Circuit Breaker) protects against overcurrent and short circuits — it is the modern equivalent of a fuse. An RCD (Residual Current Device) protects against earth leakage, which is what can kill you if you touch a live wire. Modern consumer units use RCBOs, which combine both functions into a single device per circuit, giving you the best protection. If your consumer unit still has rewirable fuses, it is overdue for an upgrade.
What should I do if I have a complete power cut in London? +
First, check whether your neighbours also have no power — if so, it is likely a supply fault and you should call your local distribution network operator (DNO), not an electrician. If it is only your property, check your consumer unit for tripped switches. If the main switch will not stay on, or keeps tripping immediately, do not keep resetting it — call an emergency electrician in London as there may be a serious fault on one of your circuits.
Why do my lights flicker in London? +
Occasional flickering is usually caused by a loose bulb or a poor connection at the light fitting. Persistent flickering across multiple lights can indicate a loose neutral connection at the consumer unit, a faulty main switch, or an issue with the incoming supply. If all lights in your home flicker simultaneously, this could be a supply-side issue — contact your DNO first. Otherwise, have an electrician in London check the connections at your consumer unit.
Can I do any electrical work myself? +
You can legally carry out minor electrical work such as replacing light switches, sockets (like-for-like), and light fittings without notifying building control. However, you must not add new circuits, work in bathrooms or kitchens (within zones), replace a consumer unit, or install outdoor wiring unless you are Part P registered. DIY electrical work is a leading cause of house fires — if you are unsure, always call a qualified electrician in London.
How long does a consumer unit replacement take? +
A consumer unit replacement in London usually takes 4 to 8 hours, depending on the number of circuits and the condition of the existing wiring. Your electricity supply will be off for most of this time, so plan accordingly — charge phones, fill flasks, and move any frozen food to a cool bag. The electrician will test every circuit before restoring power.
Is a tripping circuit breaker dangerous? +
A circuit breaker that trips occasionally is doing its job — protecting you from overcurrent. However, frequent or immediate tripping indicates an underlying fault such as a short circuit, overloaded ring main, or deteriorated cable insulation. Do not simply keep resetting it, as this bypasses the protection that is keeping you safe. Have an electrician in London diagnose the cause before using the circuit again.