Have a Next fire surround (approx 5 years old) with a built in convector heater with a bulb and pebbles to give the impression of flames. The bulb blew and tripped the fuse box. I changed the bulb and the fuse trips each time I try switching it on. Have tried changing the fuse in the plug but it still trips the main fuse when I switch it on. Any ideas how I find out what's wrong?

M Brogan, February 2012