When 'Service Phone Line' displays on keypads and reports are sent to central station when the panel is not using phone lines, verify the Phone Line Supervision setting.
The entry in Phone Supervision Time located in Panel Wide Parameters > Phone & Phone Parameters, is the number of seconds the panel will allow the phone line to be faulted before creating a phone line fail event.
Ensure Phone Supervision Time is set to 0 seconds when not supervising a phone line.