Tripping, dead circuits & faults
Electrical Fault Finding in Cardiff & Caerphilly
A trip switch that will not stay up, a circuit that has gone dead, a socket that smells hot. We find the cause rather than reset the symptom.
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The trip is the symptom, not the fault
A breaker or RCD that trips is a safety device doing its job. A circuit breaker (MCB) trips on too much current — an overload or a short circuit. An RCD trips when current is leaking to earth, which is the kind of fault that can give someone a shock. Knowing which one has gone is the first clue, so have a look before you ring: is it one switch labelled for a single circuit, or a larger switch that has taken out several?
Resetting it again and again is not a fix. If something is tripping it, the cause is still there.
What we find most often
Water in an outdoor fitting. Garden sockets, outside lights and the cable runs to them are the classic cause of an RCD that trips after rain or on damp nights.
A faulty appliance. Kettles, washing machines, dishwashers, oven elements and immersion heater elements all fail in ways that leak to earth.
Damaged cable. A screw or nail through a cable, often months after a shelf or a new kitchen went up, is one of the more common faults we trace.
Too much on one RCD. Every modern appliance leaks a tiny amount to earth. On an older split-load board where one RCD covers half the house, those small amounts add up until it trips with no single fault to find.
Loose or overheated connections. A burning smell, a crackle, a discoloured socket or a plug that is hot to the touch. Stop using it, switch that circuit off and call us.
What you can safely check first
Unplug everything on the circuit that has tripped, then reset it. If it stays on, plug things back in one at a time; if it trips when one particular appliance goes back in, you have probably found your culprit and the wiring may be fine.
If it trips with everything unplugged, the fault is in the fixed wiring or something hard-wired such as a cooker, a shower, an immersion heater or an outside light. That is the point to call us. Please do not take the cover off the consumer unit.
How we trace it
We isolate the circuits and test them individually — insulation resistance testing shows where current is leaking and how badly, and testing the RCDs themselves shows whether a device is faulty or doing exactly what it should. From there it is a matter of splitting the circuit down until the fault is cornered, then repairing it.
You get an explanation of what was wrong and what was done, in plain language. Most repairs to existing circuits are not notifiable, but in Wales work in a kitchen, a bathroom or outdoors can be — see what electrical work needs signing off in Wales.
One fault is not a reason for a new board
A circuit that trips has a fault on that circuit. Replacing the consumer unit without finding it means paying for a new board and then paying again when the fault is still there. Sometimes a board genuinely does need replacing — our consumer unit page sets out when — but that is a separate decision from fixing the fault in front of you.
Questions
Frequently asked questions
Why does my RCD trip randomly, often at night?
Intermittent trips usually follow something that changes: dew or rain getting into an outdoor fitting, a fridge or freezer running its defrost cycle, or an immersion heater coming on with a timer. The timing is a useful clue, so note when it happens.
Is it dangerous to keep resetting the trip switch?
It can be. The device is reacting to a real fault. One reset to see whether it holds is reasonable; repeatedly forcing it back on is not.
Half my house has lost power. What has happened?
On many older boards one RCD protects a group of circuits, so a fault on any of them takes the whole group off. Unplug everything on the affected side and try the reset; if it will not hold, the fault is in the wiring.
Can you come out if it happens in the evening or at the weekend?
Yes, we provide emergency cover. Ring and tell us what tripped and what is off, and we will talk you through making it safe in the meantime.
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Something keeps tripping?
Tell us what tripped, what is off and when it happens, and we will take it from there.