I have been using my DoorBell Fon for some time now. All has been well with it. There is just one thing I wish I could do that should work.
I am only able to talk on the intercom if the call is initiated from the intercom box. If someone knocks on the door, rather than ring the bell, I am not able to speak to them or unlock the door. The instructions say to pick up the phone and hit flash. That does not work for me. If it makes a difference, I'm actually using it on door 2 since that was the only way I could get a distinctive ring on my phone. I've tried pushing flash more than once with no change. (Supposedly, if connected to D2, you need to hit flash twice. But that doesn't make a difference.)
My usual phone is a cordless phone system. I had assumed this was part of the problem, but I tried plugging in a very simple, corded phone. I unplugged the other phones for this test to make sure there was no interference from the system or simply too many phones.
I asked this question of tech support for the DoorBell Fon and it took three weeks to get an answer that basically amounts to, "it works. You must not be hitting flash twice." Even without this feature working, I love the product. I'm not thrilled with tech support. Since I've seen a number of people in this group talking about it, I was hoping someone here would have a suggestion for me. the problem I've run into is the large number of people that don't want to press the call button because it doesn't look like a traditional doorbell. So they pound on the door.