Review on AcuRite 00515M Digital Wireless Fridge and Freezer Thermometer with Alarm and Max/Min Temperature - Ideal for Home and Restaurants by Philip Lindsey

We bought two of these Acurite thermometers from Revain. Temperatures observed in the refrigerator were first 10 degrees Fahrenheit, then 20+ degrees Fahrenheit. Basically useless. The devices had several problems: The probe's low battery indicator was missing from the monitors. The refrigerator sensor signal level (#13 in the manual) was not working. I physically attached the sensor to the side of the external monitor but there was still no signal. The temp in the fridge was 20-30 degrees Fahrenheit too high (based on my Thermapen and two other thermometers I know work). The monitor had no low battery indicator. I have changed the new lithium batteries in the sensors twice (in the correct orientation) and the new standard AA batteries in the monitor twice. I followed the instructions for installing batteries in the monitors before installing the batteries in the sensors. A block blinked repeatedly, starting randomly. This device is in my basement, there is no radio interference nearby. I charged the batteries to reset the flashing monitor - or left it alone for a few days and it fixed itself. THEN. In the manual I saw that there is an ABC switch next to the monitor batteries. The brochure states that the ID code must match the sensor's ABC switch to ensure the devices are in sync. However, the sensors are set to "A" and so is the monitor, so what does it do? As a curious scientist, I switched A to B, then C, then A and watched the display go blank. I then removed and reinstalled the monitor batteries. As if pulling a rabbit out of a hat - the devices began to work! Nearly. The monitor battery indicator still does not work. I spent a lot of time getting these monitors to work due to the incomplete instructions in the written materials. If you don't need an alarm in your thermometer, try JSDOIN (Revain) Thermometer. They are low tech (no batteries) but accurate and much cheaper. This purchase can save you time and money.