Not all electrical work requires a trained professional. Minor tasks such as replacing a light switch can be performed without having to notify your Local Authority Building Control Department, however they still must be done to current Building and Electrical regulation standard.

While there are a wide variety of different types of light switch you might find in the home (including pull-cord switches, narrow architrave switches and rotary dimmers), here is a guide to the most basic of them – the one-way and two-way switch. The difference between them is that two-way switches are used where there is more than one switch connected to the same light (e.g. at the top and bottom of the stairs).

Safety first

Before you start ANY sort of electrical work make sure the power is switched off at the main consumer unit OR switch off the relevant circuit breaker and lock it if you can. Then make sure that the circuit is indeed dead using a voltage tester/meter. Also take note that since 2006 the core colours inside electrical cables have changed. In the new two-core-and-earth cable, the live or phase core is insulated in a brown sheath rather than red. The neutral core is now blue as opposed to black.

What you will need:

  • Voltage tester/meter
  • Side cutters Screwdrivers
  • Green/yellow earth sleeving
  • Suitable replacement plateswitch (1 or 2-way)
  • Screws
  • Brown PVC electrical tape or sleeving

For one-way switches:

Step 1: Isolate the circuit and then confirm that the power is off using your voltage tester. Unscrew the switch faceplate and pull it forward, revealing the connections behind. These terminals will usually be marked something like L1, L2 and COM.

Step 2: Draw a diagram so that you remember which colour and number of wires were attached to each terminal. Then release the terminal screws and pull the cores from them. If the earth core is properly insulated in green/yellow sleeving and connected to the mounting box, leave this attached.

Step 3: Connect these cores to the correct terminals of the new switch, using your diagram as a reference. Tighten the screws and check they are clamping the cable cores firmly by gently tugging the wires.

Step 4: If there isn’t one already, fit a length of brown sleeving over the blue core to indicate that it is a switched live.

Step 5: If it’s not already fitted, put some green/yellow sleeving over the bare earth core of the incoming cable and connect it to the earthing terminal of the mounting box. If you’re using a metal switch, be sure to earth the switch faceplate as well.

Step 6: Double check that each connection is secure, then push the cable back into the mounting box and fit the faceplate.

 

For two-way switches:

While this is similar to a one-way switch there will normally be three cores to the cables – coloured brown (formally red), black (yellow) and grey (blue). Again these terminals will be labelled something like L1-3 and COM.

Step 1: Isolate the circuit and make sure the power is off with your voltage tester.

Step 2: Remove the faceplate from the existing switch and disconnect the cable cores.

Step 3: Note which colour goes to which terminal (write it down if you think you’ll forget!) and then transfer them to the corresponding terminals on the new switch.

 

While this is simply a brief guide to some of the electrical work you can do yourself around the home, more technical electrical work will require you to have a Part P qualification if you wish to carry it out yourself. If you are interested in learning about more work you can do or achieving Part P qualification then the best way is to learn from one of Access Training’s comprehensive electrical training courses. Offering professional qualifications to both aspiring and existing electricians as well as DIY courses, there truly is something for everyone regardless of age, gender, background or experience.

Contact Access Training on 0800 345 7492 for more information or to arrange a visit of our training facilities.