Upgrade to Elk Two-way Wireless?

[TheHeadFL]

It actually works fine probably 19 times out of 20.  But unfortunately I can't be having false alarms every 20th time I arm the alarm and then leave the house.
 
It is sunk into the door frame, at the top corner.  It is the 'recessed' type sensor, where there is a circular magnet embedded into the door itself, and a cylindrical sensor embedded in the frame itself, above where the magnet sits when the door is closed.  I am not familiar with what a plunger type sensor is.
 
It looks like this:
 
http://www.amazon.com/Interlogix-DesignLine-Wireless-Recessed-TX-1510-01-1/dp/B003Y00TAE/ref=sr_1_7?ie=UTF8&qid=1421093598&sr=8-7&keywords=ge+crystal+sensor
 
It may in fact even be that exact sensor, I am not sure since I haven't removed it.
 
Anyway, it is an inswing door with the hinge on the right side, so the sensor itself is at the top left corner.  Magnet embedded in the top of the door, sensor embedded in the top door frame.

 

[mikefamig]

It actually works fine probably 19 times out of 20.  But unfortunately I can't be having false alarms every 20th time I arm the alarm and then leave the house.
 
It is sunk into the door frame, at the top corner.  It is the 'recessed' type sensor, where there is a circular magnet embedded into the door itself, and a cylindrical sensor embedded in the frame itself, above where the magnet sits when the door is closed.  I am not familiar with what a plunger type sensor is.
 
It looks like this:
 
http://www.amazon.com/Interlogix-DesignLine-Wireless-Recessed-TX-1510-01-1/dp/B003Y00TAE/ref=sr_1_7?ie=UTF8&qid=1421093598&sr=8-7&keywords=ge+crystal+sensor
 
It may in fact even be that exact sensor, I am not sure since I haven't removed it.
 
Anyway, it is an inswing door with the hinge on the right side, so the sensor itself is at the top left corner.  Magnet embedded in the top of the door, sensor embedded in the top door frame.

An intermittent problem is going to be harder to find, I thought that the switch was dead.
 
I would pry the switch out of the door frame and replace the battery while cleaning the battery holder contacts with some electronic contact cleaner. A door is exposed to moisture and moisture creates problems with electrical contacts.
 
Mike.