After putting batteries in the intercoms, find the “Learn” button on them. Look at the pictures below to see where they are on the two available intercom styles.
Clear the memory on all intercoms. You do that by holding down the Learn button until you hear a beep and then continue holding until you hear a second beep. Then you let go of the Learn button.
Set two intercoms side by side. Press the Learn button on one intercom until you hear a beep and then release it. Within 10 seconds do the same on the second intercom. On the indoor intercoms the blue lights on the front will flash in a scanning pattern. When the scanning quits the programming is done. The intercom should emit a tone after they are programmed, but they don’t always do this.
Allow about 20 seconds after the Learn procedure if you have an outdoor style intercom since it does not have lights to tell you when programming is done.
Now press the Talk button on one intercom and see if they work. If the volume is turned up, you will get a squealing noise if the intercoms are close together. This is normal feedback and it won’t occur when the intercoms are separated.

To Program More Than Two Intercoms

After you have cleared the memory on the unit you want to add using the procedure above, take one of the programmed intercoms and set it next to one of the additional intercoms you want to program in your network.
Press the Learn button on the new intercom and release it after you hear a beep.
Within 10 seconds, press the Learn button on the intercom that is already programmed in your network and then release it.
Test the intercoms together and they should now work.

Chamberlain intercom
Outdoor Learn Button

Home Intercom
Learn button