We received the call from the town of Los Altos. The customer has a built-in Sub Zero unit. The initial problem was Sub Zero 642 refrigerator not cooling. First of all, I noticed frost buildup on the back wall in the refrigerator compartment. This for me was a clear sign of the refrigerant leak on the evaporator coil. So to make sure that my assumption is right I connected the gauge set to the compressor and measured pressure. According to the pressure, the compressor was OK. There was no refrigerant in this system.
Based on this information I offered repair to the customer. My quote included the evaporator coil replacement and recharging of the sealed system with freon. The customer gave us permission for repair. Because of often issues with Sub Zero’s evaporators we have coils for all major models in stock. Like in other many cases I was able to provide same day service.
First I disassembled the refrigerator and top grille part of the fridge. This allowed me to have access to all components which I was going to replace.
Second I cut an old coil and welded a new one. Also, I mounted the evaporator coil using screws to the back wall and connected the temperature sensor to the proper position.
Third I replaced dryer filter. Because of this repair requires recharging sealed system with new freon I always replace dryer filter. This helps a lot with freon filtration and moister removing during normal operation.
Fourth I vacuumed the condenser coil and clean the drain as a part of regular maintenance.
Finally, it is time to recharge the sealed system with proper amount of refrigerant specified on documentation which comes with the new coil. This is important because a new type of evaporators requires different freon charge than the old amount. After recharging the sealed system I let it run for 10-15 minutes and was monitoring the pressure on my gauge set. So according to the pressure sealed system was running properly.
Another happy customer!
