Did you receive a notice from Comcast? After March 6, 2012 a television set without a digital adapter will not receive any channels.
The newer flat screens will be fine, however, older TV sets (often used in bedrooms), will need an adapter.
Call Comcast  877-634-4434; or order on line www.comcast.com/digitalnow
If you decide to stop by the business office at 32nd and Dune Drive in Avalon, be sure your name is on the account. They will not allow a spouse to make any changes unless the name is specified on the account (personal experience on this).