Sorry, should have read more carefully, OK so your fuseboard is OK we will assume and the socket fizzes, the fizzing is the sound created by an electric arc either within the socket or in the immediate vacinity.
If you want to DIY I would first ensure power is off to the socket and then remove the two screws securing the faceplate, gently pull it forward, there will be red, black and green/yellow wires going into the back of it, look carefully for signs of scorching, not only on the socket but the wiring, especially where it passes through the metal backbox.
Replace the socket with a suitable type, wiring the same way - all reds to L all blacks to N all green/yel to earth (E), if the wiring is scorched see if there is enough slack to re-make the ends, otherwise B&Q sell heat shrinkable plastic sleeve and insulation tape that can be used (it's better to re-make though).
Re-Assemble and power up. You can buy a plug tester for about a fiver that tells you if you have wired it correctly.
will stress TURN OFF power before you do anything
Thanks Tony, i'll head to b+q tomorrow and get the relevant supplies to sort it out!
Thanks again for your help and advice!
All the other sockets in the flat are now back on and working fine, along with the shower pump.