"Brian Gaff" wrote in
:

We buy frost free as the defrosting is an orrible job especially
when, like me you cannot see the puddles you make and kneel in them.
Actually there is a hole and I assume it defrosts by letting the
thing
raise in temp then drain then evaporate underneath. However it does
this quite often so you don't need to worry about it. In the case of
the Freezer its working very well, and I suspect its here made to work
by a fan system and the evaporation is done outside the compartments.
Thefridge, if done this way too, could be due to a dodgy fan in that
part of the unit, not circulating the air to de humidify it.
Brian


http://www.appliance411.com/faq/howdefrostworks.shtml

The defrost system can only cope with "typical" useage. Leaving a door
open is not anticipated and the cycle gets overwhelmed.

--

DerbyBorn