Response times
What Governs the Wait, and How a Fault Spreads
The honest answer is that it depends, and it is fairer to tell you what it depends on. Where the property sits in Sussex or the wider South East matters, as does the time of day, whether anyone can be there to let an engineer in, and how dangerous the symptoms you describe sound. You are told plainly where things stand when you call, rather than handed a figure that might not hold.
The phone is answered 24 hours a day, every day of the year, nights, weekends and bank holidays included, and the call itself does real work. Describing what you can see, hear and smell lets us sort a genuine hazard from work that is better booked in. A burning smell, scorching, sparking, a shock felt from a tap, or water that has reached wiring is treated ahead of a single dead socket.
Some faults are not ours to fix, and saying so on the phone saves a wasted visit. If the whole street is dark, the fault sits on the supply side and belongs to the distribution network operator, reported free on 105. Where it is yours, turn the installation off at the main switch if it is safe to reach, leave anything scorched or wet alone, and stop resetting a breaker that will not hold.
None of that is caution for its own sake. A loose or high resistance connection gives off heat whenever the circuit is loaded, and that heat carbonises the terminal and the insulation around it, which raises the resistance further, which makes more heat again. An MCB does not see it, because it protects the cable against overload and short circuit rather than the quality of a termination. What starts at one accessory can end as cable to replace and a wall to make good.
A shock works differently. Insulation that has failed can put metalwork at a voltage it should not be at, and a circuit protective conductor that is no longer continuous is what leaves it there, because fault current has no path back to operate the protective device. Completing that path takes a person, which is why what seems harmless in a dry room is another matter in your bathroom or outdoors. Equipment suffers too, since a lost neutral can leave appliances seeing an abnormal voltage.
