On and Blinks
off approx every
20 seconds
Silent
Off and Blinks
on approx every
40 seconds
Off
Off
1 beep,
1 second
pause,
4 beeps
Blinks in
sync with
cycle of the
first beep
Blinks in
sync with
cycle of
4 beeps
Horn sounds
when no
hazard is
present
On and blinks
off approx
every 20
seconds
Blinks when
no hazard is
present
Blinks when
no hazard
is present
Condition:
Nuisance Alarm.
Recommendation:
If there is no hazard present, verify the
alarm is mounted in the correct location (see User's
Manual, "AVOID THESE LOCATIONS" section). Reset
alarm as instructed below.
4 beeps,
5 second
pause,
repeat
Off
Condition:
CO alarm when cause of alarm is known and
poses no threat.
Recommendation:
The CO Alarm Silence Feature is
activated by pressing and releasing the TEST/CO
SILENCE button on the initiating alarm while in alarm
condition. The alarm will remain silent for approx 5
minutes, depending on the level of CO detected. If CO
levels drop below alarm levels, the alarm will remain silent
and return to normal operation. If CO levels remain
constant or increase, this indicates potentially dangerous
situation and the horn will sound again. Ventilate area.
Blinks in
sync with
cycle of
4 beeps
Off
Off
POWER
GREEN LED
CO
RED LED
AUDIBLE & VISUAL SIGNALS
Silent
GAS
BLUE LED
HORN
OPERATIONAL SUMMARY
Condition:
Latching CO LED Indicator. The alarm has
previously detected CO and had alarmed.
Recommendation:
Follow the reset instructions to remove
the latching LED.
Off and
blinks on
approx every
5 seconds
until reset
Silent
Off
Condition:
Latching Gas LED Indicator. The alarm has
previously detected Gas and alarmed.
Recommendation:
Follow the reset instructions to remove
the latching LED.
Off and
blinks on
approx every
5 seconds
until reset
Previous
CO alarm or
Previous
Gas alarm
or both
* See below
_
Condition:
Alarm needs to be reset due to abnormal
operation/previous alarms.
Recommendation:
Press the TEST/RESET or PEAK/
RESET button for 10 seconds. This will clear the Alarm
LED's and clear the Silence mode. The alarm will chirp
once to indicate the reset is now complete.
MCND401 and MCND601 Series only: To reset the peak
CO memory, press and hold the PEAK/RESET button for
10 seconds until the peak level is cleared. The alarm will
chirp once to indicate the reset is now complete. The
display screen will display "000" when the peak CO level
is reset and then return to "- - -."
_
3 chirps
approx every
40 seconds
* See below
Off
Condition:
Sensor Trouble/End-of-Life/Service Alarm.
Recommendation:
Reset the alarm. If this does not clear
the problem, replace the alarm.
Off
2 chirps
approx
every 20
seconds
* See below
Off
Condition:
End-of-Service Life Alarm.
Recommendation:
Replace the alarm.
Off
Silent
Off
CONDITION / RECOMMENDATION
4 beeps,
5 second
pause,
repeat
Blinks Off when
the Red LED
blinks on
Off
Blinks in
sync with
cycle of
4 beeps
Condition:
CO alarm
Recommendation:
If a hazard is identified, please take
all precautions when an alarm sounds by calling an
Emergency Service and getting out of the home.
1 beep,
1 second
pause,
repeat
* See below
Off
Blinks in
sync with
cycle of the
first beep
Condition:
Gas alarm.
Recommendation:
If a hazard is identified, please take
all precautions when an alarm sounds by calling an
Emergency Service and getting out of the home.
* During 120 Volt Operation: On and Blinks Off approx every 20 seconds.
During 9 Volt (DC Backup) operation: Blinks On approx every 40 seconds
* See below
* See below
* See below
Turns off in
sync with
cycle of the
first beep
Condition:
AC Power is present. DC power is present.
Recommendation:
None, alarm is operating properly.
Condition:
Alarm is powered by battery backup. AC Power
is not present.
Recommendation:
Check the breaker or fuse box for power.
If the breaker or fuse box looks normal, call a licensed
electrician for assistance.
Condition:
The TEST/CO SILENCE button has been
pressed. The test sequence lasts for approximately 3
seconds after the button is released.
Recommendation:
None.
1 chirp
approx every
40 seconds
* See below
Off
Off
Condition:
Low Battery
Recommendation:
Check to make sure the battery
activation pull tab has been completely removed, battery
polarity is correct and the battery terminals are making
contact with the alarm contacts in the battery compartment.
If chirp continues, replace the 9V battery (see User's
Manual for recommended battery types).
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