I just inherited a customer(original dealer out of business) that has an Elan Z 600 controller with 2 door stations.It has to be 15yrs +. The unit works fine throughout the distributed audio system. The problem is that it will chime at random times throughout the day by itself. Any thoughts on trouble shooting this. They are an elderly couple and its little scary at 3 in the morning and the doorbell rings.
I called Elan and hit a brick wall because I am not an authorized dealer. I was thinking of starting with the door stations vs the controllers. Any suggestions would be appreciated.

Start simple. The cheap little button at the door station is available at home centers. Been years but I recall those failing often. Maybe some conductive corrosion if such exist(Ernie I like they way it sounds) has formed inside, or pushed contacts near each other. You could just undo the connection at the equipment for a day, breaking the system in half. Wiring/button or equipment.

Yep. Change the button.

Remove the bulb from the button if it's been replaced recently too. You can crack most open fairly easily, firmly- yet gently pull the bulb out then reassemble.