Electrolux ECN 1147 Operating And Installation Manual page 9

The freezer compartment will become progressively
covered with frost. This should be removed with the
special plastic scraper provided whenever the
thickness of frost exceeds ¼
A temperature rise of the frozen food packs during
defrosting may shorten their safe storage life.
Never use sharp metal tools to scrape off frost from the
evaporator as this could damage the appliance beyond
repair.