Did you know with annual maintenance your Sub-Zero refrigerator could last 30+ years? At Appliance Marshall Repair, we strive to maintain your investment to ensure a long life for your appliances. In this article, we'll talk about some of the maintenance concerns with these refrigerators that are critical to longevity and uninterrupted operation. Sub- Zero refrigerators have very efficient cooling systems, using dual compressors and dual evaporators, both the refrigerator side and freezer side are able to run independently of one another. This allows for precise temperature management and better humidity control. However, their condenser, the primary component that allows for the removal of the heat from inside the unit, is shared by both refrigerator and freezer sections. The condenser fan draws cool, roomtemperature air and removes the heat produced by the condenser. This air is then blown across the pair of compressors to help cool them and remain at a proper operating temperature. Part of keeping this process comfortably going is where annual service comes in. The cleaning of the condenser coil is critical to keeping the compressors cool and creating an efficient heat transfer back into the room air. Condensers require annual vacuuming and, on some models and ages of machines, also require to be blown out with compressed air. Generally, every 5 years a compressed air flush becomes a key part of the visit. What we find in the course of servicing these units are the ones we see annually run less frequently (extending compressor life) and also are less expensive to operate. Having a technician get a good look at all the mechanicals of these SubZero units is key to preventing unwanted failures. Part of our comprehensive maintenance visit is a verification that all internal temperature sensors are reading within factory parameters. By checking temps on these sensors, we are able to learn the general health of the refrigeration system’s intrusive tapping into the refrigerant lines. Door gaskets on the unit are also checked by our technicians during their visit to ensure a good door seal. A consistent seal is imperative for efficient operation and food preservation as well as the longevity of door hinge bushings and closing mechanisms. We will wipe down gaskets if any tackiness is found during our process. On that note, goo, sauce, stickiness, tackiness whatever you want to call the mystery substance on the surface of door seals and door frames is often the primary cause of door seal tears and failures. Sub-Zero has always used a strong magnet and a very pliable material for their gaskets. As a result, these units seal very well- sometimes a little too well. When this occurs units can be susceptible to failure from becoming "stuck" to the frame of the machine. Eventually, the situation will metastasize to a point where the gasket will tear creating a poor seal and can even prevent the door from fully shutting. This is another key aspect to consider during a service or maintenance visit. We replace several hundred gaskets a year on these machines and about 90% of the failures were preventable. Another common point of issue on Sub-Zeros is refrigerator defrost drains clogging. Older and early production machines can develop clog issues that require manufacturer-designed repair kits to prevent drain freezing, but the vast majority of drain clogs can be resolved easily with minimal disassembly. Generally, food debris will get into the drain trough and then clog the drain tube. The result of failure is water pooling at the base of the inside floor of the refrigerator. That water will eventually make it onto the kitchen floor and when this occurs it’s not always obvious. Depending on which way your floor pitches that water could roll behind the machine and make its way into the wood floor and head south. Checking this aspect of the machine is important to a thorough maintenance visit. Lastly, we check convenience items. Most importantly all your lights are fully working on the unit- including indicator bulbs in older mechanical models and dispenser models. We come across so many machines that are down to the last bulb in the refrigerator. One unique aspect of a Sub-Zero unit is, specifically since 1994 when Sub-Zero introduced electronic displays, that the LCD display is backlit by the primary lighting. This means when we get complaints of failing or dim displays the issue is in fact the primary light bulbs have started to fail. At AMR, we strive to carry many generations of Sub-Zero light bulbs. Allowing us to manage, with the right parts, a very basic issue. In 2008, some Sub-Zeros started using water filters for icemakers and models with door dispensers as well as in many models a UV/ charcoal air filter. Newer models even come equipped with display indicators when these parts are necessary to change. We will check the status and recommend replacement if necessary. Generally, water filters are good for 6mo. -1 year and we stock our service trucks with common filters to fit these units. With the prices of new built-in refrigerators climbing and wait times for current build units running 6mo. -1 year, it may be time to give us a call and get your current machine serviced. Trust us and you'll be glad you did!