There is a fault with your Electrolux Fridge Freezer ENB386, it sounds like the freezer evaperator (part that makes the ice) isn't defrosting itself.you could try switching the machine off for 24 hours so the ice melts then switch back on & see what happens.
If the fault re-occurs then there is a fault with the defrost heater, defrost thermostats or main control board.( you would need a engineer to repair is any of these parts are required. If the evaporator isn't excessivley iced up check the freezer fan this sometimes seizes, good luck.
http://www.candmdomesticappliances.co.uk
www.candmdomesticappliances.co.uk, December 2009