If you have four single-line wall jacks installed in your home/office, you must use adapters/couplers (not
included) to combine the four single telephone lines into two dual lines. The adapter/coupler may look similar to
the one pictured here and can be purchased from your local telephone products retailer.
Adapter/coupler LINE 3 + 4
NOTE: To use four lines, you must have four telephone lines with unique telephone numbers. If you only have one telephone line, this
phone will still operate, but only as a single line telephone.
Unit Initialization:
After you connect the power supply and Line 1 to the unit, the system automatically searches for and sets up a
phone ID. To set your own Phone ID, or change your phone ID, follow the steps in the Phone ID section.
You may connect up to 16 RCA 25404 and/or RCA 25403 phones to the system at one time. Features like
intercom, page and call transfer may be used among the units, but Line 1 must be common for all 25404 or
25403 units for these features to work properly. You may choose to share or privatize lines 2, 3 and 4.
Connections & Setup
Adapter/coupler LINE 1 + 2
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