ADT Water and Temperature Sensor will not reset or needs to be reset safely

The checks in more detail

which for many wireless sensors means reinserting the battery or opening the case, so that it sends its signal. The panel confirms with a beep or a message, and you name the zone, for example basement, so alerts make sense. SafeWise's guide says the sequence varies by panel model. Before a reset, check the easy causes: a weak battery, a damp or corroded probe, or a sensor out of range of the panel. Wipe the probes dry and clean with a soft cloth, because a film of damp or mineral deposit can hold a wet reading. Moisture in the case can corrode the contacts, so check the seal.

Place the sensor flat on the floor where water would collect, with the probes down, and away from a floor drain that keeps it permanently damp. After enrolling, test it with a few drops of water on the probes as the manual allows, check the panel or app reports a leak, then dry it and check the alert clears. If you sell the house or move the sensor to another room, delete the old zone. A sensor that will not enrol with a fresh battery should be replaced, because a failed leak sensor gives no warning, and the cost of a leak is far more than the sensor.

Do not reset the whole panel yourself. Think about where the sensor will do most good before you settle the position. The commonest leaks start at the washing machine hoses, the water heater, a dishwasher supply line, the sump pit and under a kitchen or bathroom sink, so a sensor at each of those is worth more than several in dry rooms. Keep the sensor out of a spot that is regularly mopped, because routine moisture will keep it in alarm. If the sensor also reports temperature, note the reading it gives in a warm room and compare with a thermometer, so you know it is sound.