Hello Mark I have the same problem, I have replaced the heater element and the sensor temperature and still no joy I am about to order another sensor as there is too types in there, if this works I will let you know, but it could be any of them on yours. What happens is the element is not heating up to defrost the chiller and it over freezes. If you need any parts try this web site, http://www.4mysamsung.co.uk. However for £100 pounds you can get an engineer out to repair it for you including parts I would recommend that, rather than fixing it yourself check the above web site for the call out details. Regards Shane Graham
Shane Graham, August 2009