samsung rs21dcns?

Obviously the defrost element isn't being brought into play, sadly this is a common problem with this appliance. You can check the sensors and element, and should have continuity through a thermal fuse. Worst case is evap assy required - comes complete with elements and stats - rough costs anywhere between £70 - £120 but you'll need a trained engineer to take the gas out of the system to fit the evap assy and put it back in up to pressure, so factor that in too, then obviously the VAT... not particularly cheap but better than a new one.

BFT
March 2008