Often we have come across a lot of mistakes with Fuse changes. The IEE Code of Practice states that "the manufacturer's recommendations should be followed" so if the manufacturer had already fit a certain rated fuse you should replace with the same rating.

If it is unknown what the manufacturing recomentations are (missing fuse etc) then the guidelines are simple:

Any appliance under 700 watts fit a 3 amp fuse should be fitted.

Any apliance over 700 watts you should fit a 13 amp fuse.

Some manufacturers of IT equipement will fit a 5 amp fuse You should always fit it with the same rating (5amp).

It is that simple.

On some DIY sites I've been on they have recommended anything from 1amp to 13amps. these are the old guidelines. some still argue that we should fit 10 amp fuses but again that is old guidelines the above are the approved guidlines and should be followed. Besides outside the above ratings it is very hard to find the other fuse ratings now days.

Other things to keep in mind is that the fuse is at standard BS 1362 and is approved. An ASTA mark shows that its approved.