First Alert FA120C - Manual (Page 26)

Р 2 6 Р
TROUBLE CONDITIONS
"Check" and
"Battery" Displays
Not all systems use
wireless sensors.
The word CHECK on the keypad's display, accompanied by a "beeping"
at the keypad, indicates a trouble condition in the system.
To silence the beeping for these conditions, press any key.
1. A display of "CHECK" and one or more zone numbers indicates
that a problem exists with the displayed zone(s) and requires your
attention. If the CHECK display relates to a fire zone, CALL FOR
SERVICE IMMEDIATELY.
Determine if the zone(s) displayed are intact and make them so if they
are not. If the problem has been corrected, the display can be cleared if
you enter the OFF sequence (user code plus OFF key) twice. If the
display persists, CALL FOR SERVICE IMMEDIATELY
.
2. If there are wireless sensors in your system, the C H E C K
condition may also be caused by some change in the environment that
prevents the receiver from hearing a particular sensor. CALL FOR
SERVICE IMMEDIATELY if this occurs.