Review on Rubbermaid FGR80DC Refrigerator Freezer Cooler Fridge Thermometer - Large Mechanical Dial for Accurate Monitoring and Control by Theresa Lewis

Bought two of these to monitor a fridge (one for the freezer and one for the fridge). After replacing the evaporator fan on a 23 year old hot tub, I bought these to get my temperature settings right. Controls: AD for freezer and 1-5 for fridge. No digital control. The evaporator fan failed for weeks and the freezer coil froze. Eventually my wife found the milk too warm and I took a closer look. After the repair, I decided I needed them for proper temperature control. I started by placing both blocks in each compartment and comparing their readings. They were about 2 degrees apart, but that's their expected accuracy. Put one in each compartment and spent several days tweaking the fridge controls to get the right temperature. The dial has two red zones that indicate the ideal temperature for the freezer and refrigerator. Now I just look and make sure the gauge is in the appropriate red area and I know everything is fine. However, be aware that sometimes (about every 8 hours of run time for my fridge) a defrost cycle will run and the temperature will rise above the acceptable range until the defrost is complete and the unit has cooled down. If I'm around and hear the compressor kick in, I'll open the door and check to see if the needle is near the warm part of the right range and needs cooling. When the compressor stops, open the door and check that the pointer is on the cold side of the correct range. This is definitely a good way to keep an eye on the health of your fridge.