Domestic Electrical Troubleshooting
Electrical faults or worse, intermittent electrical issues, are really annoying. Unlike Gas and Water you can’t see or smell electrics!
Here is a quick guide to help you eliminate simple problems and avoid expensive call outs.
The advice is aimed at a competent/confident person and please remember if you’re not comfortable with it, call an expert in.
Safety is paramount with Electrics
The three most important points to remember are:
Safety, Safety and Safety!
Always turn off (Isolate) or unplug the supplies to the circuit or appliance that you are working on before you do anything.
The different between an RCD and an MCB
MCBs and RCDs are both switch devices used to protect users and equipment from any abnormal electric current activity, e.g. an electrical fault. They work by isolating the electrical supply on that circuit. But what the is difference?
MCB stands for Miniature Circuit Breaker and is an electrical switch designed to automatically work to protect an electrical circuit from damage caused by overcurrent. Its basic function is to interrupt current flow (break the circuit) after a fault is detected. These are found in pre-2008 homes generally.
RCD stands for Residual Current Device. The speed an RCD reacts is solely for human safety and can be the difference in saving your life. It prevents or minimises the risk of injury from an electric shock if you were to touch anything live (bare wires, etc.). The RCD works by detecting an imbalance in the circuit, and automatically cutting off all power before injury or electrocution can occur.
RCDs offer a far greater level of personal protection that fuses and circuit-breakers cannot. They are also a lot more sensitive. For instance, a spot light bulb blowing will trip them. They are mandatory for homes built after June 2008.
If your home was built before July 2008 and you have not upgraded your fuse boards, you may have MCBs so please be extra careful.
RCD (Residual Current Device) Has Tripped and Won’t Reset
- The problem is almost never the RCD; the problem will more than likely by an appliance causing the RCD to trip.
- Unplug all electrical appliances, including any items that turn on and off from switch spur, e.g. dishwasher switch on the splashback. Does the RCD reset now? If yes, one of the appliances is at fault. Wait about 1 minute and re-plug all the items back in, when the RCD trips, isolate that appliance. If the RCD doesn’t reset, you need to call out a qualified electrician.
Electric or Gas Boiler Not Working
- Check the fuse in the plug top or the switch spur. Gas boilers sometimes have electrical supplies, the fuse will be near the boiler or on the main fuse board.
- If replacing the fuse does not solve the problem call an electrician or gas engineer. Remember to replace the fuse with the same rating, putting a fuse in with a greater amp rating can cause you a far worse problem down the line.
Lamp Not Working
- Replace the bulb with the correctly rated bulb. If you’re not sure take the bulb to your local hardware store to get a replacement.
- Check the power cable is in good condition? Has it been damaged, perhaps with a hoover or it’s been shut in a door?
- Do you have another lamp or Kettle you could try in the socket see if that is the issue?
Spot Light Problems
- Recessed lights, down lights and spot lights use many different voltages. Is the bulb voltage rating correct? Compare the problem bulb, or bulbs, with bulbs that are working correctly – are they the same? If so swap them over to see if it is the fitting.
- Are they on a dimmer switch? Are the lamps dimmable or over rated for the dimmer switch?
- Is something covering the bulb housing, for instance loft insulation? Overheating causes many different problems.
Ceiling Light Not Working
- Replace the bulb with the correct bulb. This is usually written on the fitting somewhere.
- Many ceiling lights have transformers to change the input voltage to the bulb, this may be causing the problem. The transformer will be in the ceiling space or loft. You will more than likely need a qualified person to sort this issue out.
- Wiring coming loose is the next issue – again you will need a qualified person to sort this out.
- Usually a poor electrical connection and will more than likely require testing of the circuit or fitting connections by a trained person.
- If more than one light or bulb is flickering, check the RCDs.
Spot Lights Intermittent
- Usually this is due to overheating. Is something covering the bulb housing? For instance loft insulation? Incorrect bulb wattage – what wattage are the other bulbs (that are working), is the problem light the same wattage? Have you changed anything recently?
One Light Is Brighter or Dimmer Than the Others
- The obvious question – are the bulbs the same wattage or if LEDs, are they the same colour?
- Poor wiring to the bulb holder – is the wiring securely connected? If not, you may need an electrician.
One Bulb Blows More Often Than Others
- Bulb wattage – is the bulb correct wattage, what wattage are the bulbs that don’t blow so often?
- Poor wiring to the bulb holder, competent person required.
Electrical Socket Not Working
- Are all the electrical sockets not working or just the one?
- If no electrical sockets are working has an RCD tripped or a fuse blown? Check fuses. Check the RCDs.
- The problem could also be the wiring to the electrical socket you will need a competent person to test this.
- Tumble Dryers, Washing Machines, Microwaves, etc. will trip an RCD or MCB if faulty. You need to remove all appliances on this circuit and re-energise them 1 by 1 till you find the faulty appliance or socket.
- Plug another appliance into the electrical outlet, a lamp or kettle is perfect for this, to check if the socket is OK.
If the above info does not work and you need an electrician, giving the below information to them will speed up the repair.
- If an electrical socket is not working is it just the one socket not working or are no electrical sockets working?
- Are all ceiling lights not working or just the one?
- If a boiler is not working, does the TV and tumble-dryer still work? Have all supplies, to the house, been lost, or just to one circuit or one appliance?
- Is the problem something that is happening regularly? Is there a history of electrical problems in this room, on this circuit or in this house?
- Is it always the same bulb, fuse or RCD (Residual Current Device) that blows?
- Always check RCDs or MCBs even if you think the RCD is not the problem.
- If in any doubt please contact GHS for free advice.