Electricians Hastings Change a light switch

How to change a light switch - 3 easy steps

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How to change a light switch

You might need to replace a light switch because it is damaged or faulty or perhaps you have redecorated, and you want to update the look of the sockets you currently have, either way it is a job that can be completed successfully following a few simple steps.

First and most importantly you need to remember..............


It is important that you take these precautions to ensure it is safe to carry out electrical work and never, NEVER take risks where electricity is concerned.

  • · Make sure you switch off the mains power at the consumer unit. Identity the circuit you want to isolate and either remove the fuse and keep it on you or use a lock-off device so no one can turn the electric back on whilst you are working on it.
  • · Put a note on the consumer unit so people know you are working on t a circuit. People can assume that the circuit has tripped and innocently turn it back on putting you in danger.
  • · Using a voltage tester, you now need to make sure the circuit is dead. This will confirm to you whether the circuit is safe to work on.
  • · Keep the voltage tester handy so you can use it once the job is completed just to make sure it is safe to use.

For safety, electrical accessories must be installed in accordance with your local Building Regulations. If you are unsure, or where the law requires it, engage a competent person who is registered with an electrical certification scheme such as NICEIC. You can get details of competent persons in your area from their website.

REMEMBER to take caution when opening multiway switches, if they have been connected incorrectly they maybe taking power from another circuit you have not isolated.

Earth the switch

A light switch fitted flush with the wall will usually comprise of a plastic switch facia and a metal mounting box recessed into the wall. It is important that the metal mounting box is earthed, and this is done by connecting the earth core of the cable to the earthing terminal located in the mounting box. If you have a metal switch facia this will also need to be earthed. As there may only be one earth core available, you will need an additional length of 1mm2 earth core sleeved in yellow/green sleeving to create a bridge between the earthing terminals on the switch facia and the metal mounting box. If both your switch facia and mounting box are made of plastic neither will have an earthing terminal. In these circumstances, you still sleeve the earth core and clamp the ends with a connector. Do not be tempted to cut it off as this will cause problems later down the line if the switches are changed to metal there will be no way of earthing it.

Hastings Electrician Earth mounting box and light switch

Step 1 - Remove the switch

Once you have isolated the circuit and are satisfied the power is off by confirming with the voltage tester, it is time to remove the switch. Remove the screws from the switch and gently pull the switch away from the wall until you can see the wires and connections behind. Make sure at this point you either draw a diagram of the wiring or take a photo so you easily identify which wires are going to each terminal. Dependent on the age of your wiring you may have red and black cores denoting live and neutral respectively, or the current colours which are brown for live and blue for neutral. If you have a metal mounting box, the earthing terminal may already be attached. If it is sleeved properly there is no reason to remove it from the terminal and you can remove the switch whilst leaving the earth in place.

Step 2 - Install new switch

Now the old switch is removed you can connect the cores to the corresponding terminals on the new switch. Make sure that the terminals are tight and have gripped the cores by giving each core a firm pull.

The neutral wire (black or blue) should be sleeved with a piece of brown sleeving to show it is used as a live.

Run green/yellow PVC sleeving over the bare earth core of the switch drop cable and connect it to the earthing terminal of the mounting box. If you're using a metal switch, make sure you earth the switch faceplate.

Step 3 - Final checks

Make sure your mounting box and switch facia are earthed if required and the terminals are all tight before gently replacing the cabling and replacing the switch facia.