Modern fridges have an automatic defrost feature - every now and again they stop cooling - a gentle heat melts the beads of frost and the melt water runs out through a hole in the back wall.
It may be that your auto defrost feature is defective...
Your choices are:
Ignore it completely
Defrost the fridge yourself every now and again
Place a service call to get it repaired
Buy a new fridge
Good luck...
Clarence Birdseye
September 2014
howtomendit.com for free repair help, information and advice.
