How to change a fuse on a plug socket

Replacing a fuse, similar to changing a light bulb, is something most people are capable of but it’s easy to make a mistake so below we have provided a breakdown of how to change a fuse and how to avoid some potentially dangerous pitfalls If you are not confident and would like a qualified electrician to carry out this work, or you have additional electrical work that needs attention don’t hesitate to  contact us.

Fuses for 3 pin plugs are all the same physical size but have different ratings and each fuse should be identifiable by colour and the rating should be marked clearly on the fuse. The most common ratings are:

• 3A – red
• 5A – black
• 13A – brown

When the time comes to replace a fuse, it should always be a like for like replacement that matches the specification for the equipment being used. Changing a fuse rating (without a good understanding of why you are doing so) is potentially risky:

Replacing a fuse with a smaller one will likely cause you issues whereby the fuse will blow during normal operation and may damage the item it’s connected to.

Changing a fuse for a larger one (which is often tempting if a fuse blows regularly) is potentially very dangerous; fuse ratings are chosen for the product they supply to ensure that the amount of current drawn by the item doesn’t exceed a certain threshold. If it is exceeding this threshold there may be a fault and increasing the fuse size could potentially cause a fire or electrocution!

How to Change a fuse in a standard 3 pin plug:

Before you start, you need to ensure the plug is disconnected from the mains and then identify the type of plug you have:

A moulded plug will usually have a pop out fuse holder between the pins.

A standard plastic plug typically has the fuse internally mounted and needs to be opened up.

A moulded plug is generally very easy to replace the fuse on – the fuse holder is popped out using a small flat bladed screwdriver or similar and then a new fuse can be seated and the holder reinstated. Again always check you are matching fuses like for like (or understand why you are changing the fuse rating if you are).

For a standard plug you will need a screwdriver (usually a flat headed screwdriver but will depend on the screws in that particular plug – take a look at the base).

1. In an anti-clockwise direction, loosen the screw(s) – typically this type of plug will have a larger central screw that holds the cases halves together; that’s the one to go for. You may not need to remove all the screws completely as the back of the plug should come away following a few turns of the screws.
2. Open the case and keep the back and the screw in a safe place for reinstating later.
3. Pull the fuse out, you will find the fuse within two metal holders inside the plug, sometimes these can be tight and need to be prised out, don’t worry if one of the pins lifts out with it initially – this just slides back through the case once the fuse is removed.
4. Replace the old fuse with a new fuse (making sure it’s like for like or that you really understand why it’s changing if it is).
5. It’s often worth just checking the terminals (the small screws that hold the cables in the plug) are tight at this point – a loose connection can cause overheating and an increase in current which may be why the fuse blew initially). Just try to tighten them with (usually) a small flat blade screwdriver to make sure they are nice and tight.
6. Return the lid of the plug and screw firmly. When secure there should be no movement from the metal pins that go into the wall socket.
7. If the fuse blows again, there may be an electrical fault not associated with the fuse. In this instance, we would recommend an electrician to carry out an electrical safety inspection to check the product.

If you are unsure if your product is safe, consult an electrician. Alternatively, if you want to contact us to perform a one off job you can read about our electrician services here.