Hotpoint model 8596P Mistral Plus frost free Fridge Freezer. The tempreture went up + 19 degrees in the fridge section. I cleaned out the air intake at floor level and was surprised at the amount of fluff on the grid (whatever it is called). I have checked the tempreture sensor and both fans rotate. Now some 12 hours later the fridge section internal tempreture reads +5 degrees but I have an E8 flashing in the digital display. Help.......What does this E8 mean......