What sensors can I use on my Elertus smart sensor?

• The Elertus smart sensor comes with one accessory plug, but you can get a Y cable to use a second accessory on this unit.  Your accessory options include a door sensor, a water sensor, and an external temperature sensor. 
• If you are using the Y cable you can use the door sensor with a second door sensor or a temperature probe, but not a water sensor.
• You can also use a water sensor with a second water sensor, or with a temperature sensor.
• You cannot use one door sensor with one water sensor.  If you want to monitor a door as well as monitor for a water leak you will have to get two smart sensors, and get one of the probes for each.