Diagnosing an IOLinc connected to a Doorbell

After the post on adding your doorbell to your Insteon network, reader Steve was having some problems:

I have tried for days to set up my doorbell to my insteon network/isy-994i and it doesn't seem to work for me.  My doorbell has two wires and it's wired right into my basement to the side of an electrical box.  Doorbell is lighted and has power from that electrical box in basement.  When I try to connect leads into iolinc per your instructions I don't get any power to light up doorbell.

The key word to the problem immediately jumped out, as I had the same issue: he mentioned it was a lighted doorbell. The problem boiled down to having to choose between a lighted doorbell and having it integrate with the I/O Linc. In my case, I was able to get the system to work by simply unscrewing the doorbell mechanism and removing the light bulb – but it will depend on the actual mechanics of your bell.

The IOLinc detects a “closed circuit”, and the light bulb “closes” that circuit. Removing the light bulb allows the circuit to open when the button is not being pressed. With the light bulb present, the voltage difference effectively “closes the circuit” so the IOLinc interprets this as someone holding down the button.

If you’re having problems wiring your IOLinc to your doorbell – or any other device for that matter, try these steps to diagnose the issue:

1. Connect the Output of the IOLinc to the doorbell transmitter.
2. Add the IOLinc to the ISY994i.
3. Using the admin interface of the ISY, try turning the output of IOLinc “on”. If the doorbell transmitter is connected to the receiver, it should ring at this point.
4. Next, connect two regular wires to the inputs as described in the post (GND and S). Now, when you look at the IOLinc input in the admin interface, if you touch those two wires together, the input state should change between “Off” and “On”. Note that this has nothing to do with the doorbell at this point – we’re just confirming that the input terminals are working. If the wires are touching, the input should read “ON”, and if they are not, the input should read “Off”.
5. Now here’s where I suspect you may be having an issue with your lighted doorbell: if you replace those regular two wires with the two wires coming from your doorbell (cut away from your existing doorbell box), and the lightbulb is still in, I suspect you’ll see two things:
1. The light on the doorbell doesn’t work. That’s because the IOLinc isn’t sending any power on those terminals like the old doorbell system did.
2. The admin interface will show “ON” for the IOLinc, regardless of whether the button is pressed or not. That’s because the light bulb inside the doorbell button allows just enough current through to “close” the circuit
6. If you confirm 5(b), try repeating step #5 after removing the bulb. If you’re still not able to get the admin interface to show the input state toggling between on and off, you might need to replace the button itself with one that doesn’t have a light.
7. Finally, once you can see the input state changing between on and off in the ISY admin interface, you can tie together the input with the output as discussed in that post