20 Most Recent Sub-Zero 690 Side by Side Refrigerator - Page 8 Questions & Answers

b)The tube or thermostat is frozen, most likely because someone left the door open or the seal is poor;

c) termostat defective-untube video explained how to test circuit; 4. CONDENSER ISSUES: the condenser coolant gas is low and can be easily recharged- see the u tube how to video; 5. Condenser is dirty and cannot breathe- vacuum it; 6. The condenser overheated and needs replacing . 4-6 will have the condenser blowing cool not warm air. I have had this problem with the fridge portion of my SUBZERO bottom freezer and Subzero (and a repair person ) gave me some good advice, which should also apply to yours, but you might want to call them yourself: 1. Simplest fix- if the defrost tube is blocked or frozen, the defrost cycle will stick on preventing cooling (either freezing up or heating for the defrost cycle not cooling); Some subzero models are especially prone to this. I could see part of my tube inside the fridge on the back wall close to the bottom where it drains and removed the panels to expose and clean it; 2. You should pull it out and unplug it to get it to defrost fully. After doing that once, I made sure my fridge was on a separate circuit or switched!! Yours might not be the same, but on mine the tubes run through the fridge to get to the freezer so both parts have to defrost; 3. Subzero fridge and freezer each have their own independent condensers, so you might be hearing the condenser for the fridge running, even though one part is turned off. 4. Check the thermostat to see if it is working. There is a good u tube video on this. 5 Some of the u tube videos show how to "recharge" the Freon. Subzero told me these are sealed units and could not be done, so regardless of the problem, the condenser had to be replaced. The subzero repair person was really helpful + checked the Freon or gas level (Mine was old enough that it was Freon not the newer environmental stuff) so they would have to haul it away to drain and recharge it + then the condenser might still have to be replaced.

Good luck

Joan