First Alert CO615 User Manual

NORMAL AC POWER

LED is Green.

BATTERY BACK-UP POWER

Red LED is flashing once every 45
seconds.

DURING TESTING

LED flashes Red in sync with the
horn, simulating an Alarm condition.

LOW OR MISSING BATTERY

Green LED On if AC power is present

CARBON MONOXIDE ALARM

LED flashes Red in sync with horn

MALFUNCTION SIGNAL

LED flashing Red 3 times in sync 
with 3 rapid chirps

LOW BATTERY SILENCE

LED is Green.

PRE-ALARM CONDITION 
CO IS PRESENT

Green power LED On if AC power is
present

Silent

Flashing battery icon.

The CO alarm horn pattern 
(4 beeps, pause, 4 beeps) is issued.

During the simulated
CO alarm, “CO” is
displayed along with
a full alarm level.

Several ppm CO 
levels are also 
displayed and 
the alarm level is
shown increasing.

A chirp is issued about every
minute.

Battery icon will show
an empty icon.

3 rapid chirps every minute

“ERROR” is displayed.

Silent

“SILENCE” is displayed.

Repeating 4 beeps, pause

“CO” alternating 
with the ppm 
number, a full level,
and “EVACUATE”.

Silent

“CO” alternating with the ppm number.
The level will indicate relative CO 
exposure level.

Silent

All segments 
of display are
turned on for 
a short time
upon initial
power. Then
the battery level icon is displayed.