Question

Own a couple of SmartThings water sensors which also sense temperature. Can I place them in a refrigerator? What's the temperature range for these and is it okay to leave it there for an extended time. I never had to do any calibration with these devices as it relates to temperature but when I place one of them in the refrigerator he was about 18 degrees off. Is that normal

Answer 1

Yes but it may shorten battery life.  

Answer 2

Temperature range will work in a normal fridge and even refrigerator. Tried that a few times (with a temperature sensor from aqara though), but they always lost connection after a few days. Due to the metal cladding of the devices, I guess. I use one waterleak sensor right under the wastewater hose of my dishwasher. With its ability to measure the room temperature, I could get a signal when the hot water is drained from the washer and with a established delay, I get a light notification, when the cleaning cycle is ready.  

Answer 3

Not all devices can measure down to freezer temps. I use the Smartthings buttons, they go down to zero F (look at the specs). Generally, wireless devices inside a fridge seems to like to go offline more often than those outside, probably because of the poorer connection and the low temp especially in the freezer dropping the battery voltage. Might be a good idea to have something else close to maximize signal strength. All three of mine look like the battery is about to die but they seem to last anyways.