This unit has a recurring problem with the defrost timer. after the first 10 years the original part
gave up. we had it replaced and (as normal for me i watched very closely) . after 2 years the same trouble started again. the defrost cycle would run to long. so i replaced the same part and solved the trouble again. so now about every 2 years this part wears out again and i order it and replace it. this has gone on for 20 years now and this unit is still going strong after serving us for 29 years with the continued replacement of this one part.