CO Alarm go s back into alarm 4 minut s aft r you
pr ss th  T st/Sil nc  button. CO l v ls indicat  a pot ntially dang rous situation. IF YOU ARE FEELING SYMPTOMS OF CO 
POISONING, EVACUATE your hom  and call 911 or
th  Fir  D partm nt. If not, pr ss th  T st/Sil nc 
button again and keep ventilating your home.
Th  light flash s (RED) and th  horn sounds 
3 “chirps”  v ry minut . MALFUNCTION SIGNAL. CO Alarm n ds to b 
r plac d. CO Alarms und r warranty should b  r turn d to 
manufactur r for r plac m nt. S  “Limit d
Warranty” for d tails.
PROBLEM... THIS MEANS... YOU SHOULD...
Th  light continu s to flash (RED) and th  horn
“chirps” onc   v ry minut . Low batt ry warning. Install a n w 9V alkalin  batt ry*.
WHERE TO INSTALL CO ALARMS, Continued
In a Single-level Home:
• Install at l ast on  CO Alarm n ar or within  ach s parat  sl ping ar a.
•For add d prot ction, install an additional CO Alarm at l ast 20 f t 
(6 m t rs) away from th  furnac  or fu l burning h at sourc .
In a Multi-level Home:
•Install at l ast on  CO Alarm n ar or within  ach s parat  sl ping ar a.
• For add d prot ction, install at l ast on  CO Alarm on  ach l v l of th 
hom .
•For add d prot ction, install an additional CO Alarm at l ast 20 f t
(6 m t rs) away from th  furnac  or fu l burning h at sourc .
In Mobile Homes:
•Install CO Alarms on insid  walls ONLY. Uninsulat d outsid  walls and
roofs of mobil  hom s oft n transf r h at and cold from outdoors. Th 
Alarm should b  locat d at l ast 152 mm (6 inch s) from all  xt rior walls
and at l ast 305 mm (12 inch s) from supply or r turn v nts.
WHERE CO ALARMS SHOULD NOT BE
INSTALLED
DO NOT LOCATE THIS CO ALARM:
• In garag s, kitch ns, furnac  rooms, or in any  xtr m ly dusty, dirty or
gr asy ar as.
• Within 5 f t (1.5 m t rs) of any cooking applianc .
• In  xtr m ly humid ar as. This alarm should b  at l ast 10 f t (3 m t rs)
from a bath or show r, sauna, humidifi r, vaporiz r, dishwash r, laundry
room, utility room or oth r sourc  of high humidity.
• In ar as wh r  t mp ratur  is cold r than 40˚F (4.4˚C) or hott r than 100˚F
(37.8˚C). Th s  ar as includ  uncondition d crawl spac s, unfinish d
attics, uninsulat d or poorly insulat d c ilings, porch s, and garag s.
• In turbul nt air, lik  n ar c iling fans, h at v nts, air condition rs, 
fr sh air r turns, or op n windows. Blowing air may pr v nt CO from
r aching th  s nsors.
• Outsid  th  Mobil  Hom .
• In dir ct sunlight.
•  This CO Alarm is designed for use inside a single-family home or
apartment. It is not meant to be used in common lobbies, hallways,
or basements of multi-family buildings unless working CO Alarms
are also installed in each family living unit. CO Alarms in common
areas may not be heard from inside individual family living units.
•  This CO Alarm alone is not a suitable substitute for complete
detection systems in places which house many people, like hotels
or dormitories, unless a CO Alarm is also placed in each unit.
•  DO NOT use this CO Alarm in warehouses, industrial or commercial
buildings, special-purpose non-residential buildings, or airplanes.
This CO Alarm is specifically designed for residential use, and may
not provide adequate protection in non-residential applications.
CO ALARM
S nsor has d t ct d  nough CO to trigg r an alarm. Light flash s rapidly 
and horn sounds loudly (r p ating 
4 b ps, paus )
. S  “If Your CO Alarm
Sounds” for d tails. During an alarm, move everyone to a source of fresh
air. DO NOT move the CO Alarm!
DURING TESTING
Light flash s R d with th  horn patt rn 
(4 b ps, paus , 4 b ps)
, simulating
a CO Alarm condition.
© 2012 BRK Brands, Inc. All rights r s rv d. Distribut d by BRK Brands, Inc.
3901 Lib rty Str t Road, Aurora, IL 60504-8122
Consum r Affairs: (800) 323-9005
www.brk l ctronics.com   •   www.firstal rt.com
INTRODUCTION
BASIC SAFETY INFORMATION
• Dangers, Warnings, and Cautions alert you to important operating
instructions or to potentially hazardous situations. Pay special 
attention to these items.
• THIS IS NOT A SMOKE ALARM! This CO Alarm is designed to detect
carbon monoxide from ANY source of combustion. It is NOT designed
to detect smoke, fire, or any other gas.
• This CO Alarm is approved for use in single-family residences. 
It is NOT designed for marine use.
•This CO Alarm will only indicate the presence of carbon monoxide gas
at the sensor. Carbon monoxide gas may be present in other areas.
•The Silence Feature is for your convenience only and will not correct
a CO problem. Always check your home for a potential problem after
any alarm. Failure to do so can result in injury or death.
•NEVER ignore your Carbon Monoxide Alarm if it alarms. Refer to 
“If Your CO Alarm Sounds” for more information. Failure to do so
can result in injury or death.
• Test the CO Alarm once a week. If the CO Alarm ever fails to test 
correctly, have it replaced immediately! If the CO Alarm is not working
properly, it cannot alert you to a problem.
•This product is intended for use in ordinary indoor locations of family
living units. It is not designed to measure CO levels in compliance
with Occupational Safety and Health Administration (OSHA) commer-
cial or industrial standards. Individuals with medical conditions that
may make them more sensitive to carbon monoxide may consider
using warning devices which provide audible and visual signals for
carbon monoxide concentrations under 30 ppm. For additional 
information on carbon monoxide and your medical condition contact
your physician.
HOW YOUR CO ALARM WORKS
GENERAL INFORMATION
•This CO Alarm does not operate without working batteries.
Removing the batteries, or failure to replace them at the end of their
service life, removes your protection.
A CO Alarm m asur s th  CO l v ls in th  air. It will alarm if CO l v ls ris 
quickly (if th  h at  xchang r on your furnac  br aks, for  xampl ), or if CO 
is consist ntly pr s nt (a slow CO l ak on a fu l-burning applianc ). 
This Carbon Monoxid  Alarm f atur s a p rman ntly install d s nsor and an
85 dB alarm horn. It also has a sil nc  f atur  to t mporarily qui t th  alarm
horn.
1 2 3 4 5
LIMITED WARRANTY
BRK Brands, Inc. ("BRK") th  mak r of BRK®brand and First Al rt®brand products, warrants that for a p riod of s v n y ars from th  dat  of purchas , this product
will b  fr  from d f cts in mat rial and workmanship. BRK, at its option, will r pair or r plac  this product or any compon nt of th  product found to b  d f ctiv 
during th  warranty p riod. R plac m nt will b  mad  with a n w or r manufactur d product or compon nt. If th  product is no long r availabl , r plac m nt may
b  mad  with a similar product of  qual or gr at r valu . This is your  xclusiv  warranty.
This warranty is valid for th  original r tail purchas r from th  dat  of initial r tail purchas  and is not transf rabl . K p th  original sal s r c ipt. Proof of purchas 
is r quir d to obtain warranty p rformanc . BRK d al rs, s rvic  c nt rs, or r tail stor s s lling BRK products do not hav  th  right to alt r, modify or any way
chang  th  t rms and conditions of this warranty.
This warranty do s not cov r normal w ar of parts or damag  r sulting from any of th  following: n glig nt us  or misus  of th  product, us  on improp r voltag 
or curr nt, us  contrary to th  op rating instructions, disass mbly, r pair or alt ration by anyon  oth r than BRK or an authoriz d s rvic  c nt r. Furth r, th  
warranty do s not cov r acts of God, such as fir , flood, hurrican s, and tornado s. Th  Lithium Batt ry suppli d with this unit is warrant d to last for fiv  y ars.
BRK shall not b  liabl  for any incid ntal or cons qu ntial damag s caus d by th  br ach of any  xpr ss or impli d warranty. Exc pt to th   xt nt prohibit d by
applicabl  law, any impli d warranty of m rchantability or fitn ss for a particular purpos  is limit d in duration to th  duration of th  abov  warranty. Som  stat s,
provinc s, or jurisdictions do not allow th   xclusion or limitation of incid ntal or cons qu ntial damag s or limitations on how long an impli d warranty lasts, so 
th  abov  limitations or  xclusion may not apply to you. This warranty giv s you sp cific l gal rights, and you may also hav  oth r rights that vary from stat  to
stat , or provinc  to provinc .
How to Obtain Warranty Service
Service: If s rvic  is r quir d, do not r turn th  product to your r tail r. In ord r to obtain warranty s rvic , contact th  Consum r Affairs Division at 1-800-323-9005,
7:30 AM to 5:00 PM, C ntral Standard Tim , Monday through Friday. To assist in s rving you, pl as  hav  th  mod l numb r and dat  of purchas  availabl  wh n
calling.  For Warranty Service return to: 25 Spur Driv , El Paso, TX 79906
Battery: BRK Brands, Inc. mak s no warranty,  xpr ss or impli d, writt n or oral, including that of m rchantability or fitn ss for any particular purpos , with r sp ct
to batt ry.
6
UNDERSTANDING YOUR CO ALARM
LOW BATTERY WARNING
Th  light continu s to flash (RED) and th  horn also “chirps” onc   v ry
minut . This warning should last for up to 30 days, but you should r plac  
th  batt ri s as soon as possibl .
WELCOME CHIRP
Horn chirps and light blinks onc  wh n batt ri s ar  first conn ct d.
ALARM RECEIVING BATTERY POWER
Light flash s  v ry minut . Horn is sil nt.
CO ALARM REQUIRES SERVICE (MALFUNCTION SIGNAL)
Th  light flash s (RED) and th  horn sounds 3 “chirps”  v ry minut . 
CO Alarm n ds to b  r plac d.
CO ALARM HAS REACHED ITS END OF LIFE
Th  light flash s (RED) and th  horn sounds 5 “chirps”  v ry minut . 
CO Alarm n ds to b  r plac d.
WHERE TO INSTALL CO ALARMS
Th  National Fir  Prot ction Association (NFPA) r comm nds that a CO Alarm
should b  c ntrally locat d outsid  of  ach s parat  sl ping ar a in th 
imm diat  vicinity of th  b drooms. For add d prot ction, install additional
CO Alarms in  ach s parat  b droom, and on  v ry l v l of your hom .
If your b droom hallway is long r than 40 f t (12 m t rs), install a CO Alarm
at BOTH  nds of th  hallway.
This alarm can b  install d on th  wall or c iling. If th  alarm is to b  wall
mount d it is r comm nd d that th  unit b  mount d with hing  down so 
th  words "Carbon Monoxid  Alarm" is r adabl .
INSTALLATION
Read “Where To Install CO Alarms” before starting.
Before you start installation, find th  pair of s lf-adh siv  lab ls includ d
with this CO Alarm. On  ach lab l writ  in th  phon  numb r of your  m r-
g ncy r spond r (lik  911) and a qualifi d applianc  t chnician. Plac  on 
lab l n ar th  CO Alarm, and th  oth r lab l in th  “fr sh air” location you
plan to go if th  alarm sounds.
IF YOUR CO ALARM SOUNDS, Continued
Alarms have various limitations. See "General Limitations of CO Alarms"
for details.
USING THE SILENCE FEATURE
•  The Silence Feature is for your convenience only and will not 
correct a CO problem. Always check your home for a potential
problem after any alarm. Failure to do so can result in injury or
death.
•  NEVER remove the batteries from your CO Alarm to silence the
horn. Use the silence feature. Removing the batteries removes 
your protection! See “If Your CO Alarm Sounds” for details on
responding to an alarm.
Th  Sil nc  F atur  is int nd d to t mporarily sil nc  your CO Alarm’s alarm
horn whil  you corr ct th  probl m—it will not corr ct a CO probl m. Whil 
th  alarm is sil nc d it will continu  to monitor th  air for CO.
Wh n CO r ach s alarm l v ls th  alarm will sound— r p ating horn patt rn:
4 b ps, a paus , 4 b ps,  tc. Pr ss and hold th  T st/Sil nc  button until
th  horn is sil nt. Th  initial Sil nc  cycl  will last approximat ly 4 minut s.
NOTE: Aft r initial 4-minut  Sil nc  cycl , th  CO Alarm r - valuat s pr s nt
CO l v ls and r sponds accordingly. If CO l v ls r main pot ntially dang rous
—or start rising high r—th  horn will start sounding again.
While the detector is silenced:
If the CO Alarm... 
Is sil nt for only 4 minut s, th n
starts sounding loudly—4 b ps,
paus , 4 b ps, paus 
This means...
CO l v ls ar  still pot ntially 
dang rous.
If the CO Alarm...
R mains sil nt aft r you pr ss d
th  T st/Sil nc  button
This means...
CO l v ls ar  dropping.
WHAT YOU NEED TO KNOW ABOUT CO
WHAT IS CO?
CO is an invisibl , odorl ss, tast l ss gas produc d wh n fossil fu ls do not
burn compl t ly, or ar   xpos d to h at (usually fir ). El ctrical applianc s
typically do not produc  CO.
These fuels include: Wood, coal, charcoal, oil, natural gas, gasolin ,
kros n , and propan .
Common applianc s ar  oft n sourc s of CO. If th y ar  not prop rly main-
tain d, ar  improp rly v ntilat d, or malfunction, CO l v ls can ris  quickly.
CO is a r al dang r now that hom s ar  mor   n rgy  ffici nt. “Air-tight”
hom s with add d insulation, s al d windows, and oth r w ath rproofing
can “trap” CO insid .
SYMPTOMS OF CO POISONING
Th s  symptoms ar  r lat d to CO POISONING and should b  discuss d
with ALL hous hold m mb rs.
Mild Exposure: 
Slight h adach , naus a, vomiting, fatigu  (“flu-lik ” symptoms).
Medium Exposure:
Throbbing h adach , drowsin ss, confusion, fast h art rat .
Extreme Exposure:
Convulsions, unconsciousn ss, h art and lung failur . Exposur  to carbon
monoxid  can caus  brain damag , d ath.
Some individuals are more sensitive to CO than others, including people
with cardiac or respiratory problems, infants, unborn babies, pregnant
mothers, or elderly people can be more quickly and severely affected by
CO. Members of sensitive populations should consult their doctors for
advice on taking additional precautions.
FINDING THE SOURCE OF CO AFTER AN ALARM
Carbon monoxid  is an odorl ss, invisibl  gas, which oft n mak s it difficult
to locat  th  sourc  of CO aft r an alarm. Th s  ar  a f w of th  factors that
can mak  it difficult to locat  sourc s of CO:
• Hous  w ll v ntilat d b for  th  inv stigator arriv s.
•Probl m caus d by “backdrafting.”
• Transi nt CO probl m caus d by sp cial circumstanc s.
B caus  CO may dissipat  by th  tim  an inv stigator arriv s, it may b  
difficult to locat  th  sourc  of CO. BRK Brands, Inc. shall not be obligated
to pay for any carbon monoxide investigation or service call.
HOW CAN I PROTECT MY FAMILY?
A CO Alarm is an  xc ll nt m ans of prot ction. It monitors th  air and
sounds a loud alarm b for  carbon monoxid  l v ls b com  thr at ning 
for av rag , h althy adults.
A CO Alarm is not a substitute for proper maintenance of home appliances.
To h lp pr v nt CO probl ms and r duc  th  risk of CO poisoning:
• Cl an chimn ys and flu s y arly. K p th m fr  of d bris, l av s, and
n sts for prop r air flow. Also, hav  a prof ssional ch ck for rust and 
corrosion, cracks, or s parations. Th s  conditions can pr v nt prop r
air mov m nt and caus  backdrafting. N v r “cap” or cov r a chimn y 
in any way that would block air flow.
• T st and maintain all fu l-burning  quipm nt annually. Many local gas or
oil compani s and HVAC compani s off r applianc  insp ctions for a
nominal f .
• Mak  r gular visual insp ctions of all fu l-burning applianc s. Ch ck appli-
anc s for  xc ssiv  rust and scaling. Also ch ck th  flam  on th  burn r
and pilot lights. Th  flam  should b  blu . A y llow flam  m ans fu l is not
b ing burn d compl t ly and CO may b  pr s nt. K p th  blow r door
on th  furnac  clos d. Us  v nts or fans wh n th y ar  availabl  on all
fu l-burning applianc s. Mak  sur  applianc s ar  v nt d to th  outsid .
Do not grill or barb cu  indoors, or in garag s or on scr n porch s.
• Ch ck for  xhaust backflow from CO sourc s. Ch ck th  draft hood 
on an op rating furnac  for a backdraft. Look for cracks on furnac  
h at  xchang rs.
• Ch ck th  hous  or garag  on th  oth r sid  of shar d wall.
• K p windows and doors op n slightly. If you susp ct that CO is  scaping
into your hom , op n a window or a door. Op ning windows and doors
can significantly d cr as  CO l v ls.
In addition, familiarize yourself with all enclosed materials. Read this
manual in its entirety, and make sure you understand what to do if your
CO Alarm sounds.
WHAT LEVELS OF CO CAUSE AN ALARM?
Und rwrit rs Laboratori s Inc. Standard UL2034 r quir s r sid ntial CO
Alarms to sound wh n  xpos d to l v ls of CO and  xposur  tim s as
d scrib d b low. Th y ar  m asur d in parts p r million (ppm) of CO ov r
tim  (in minut s).
UL2034 Required Alarm Points*:
• If th  alarm is  xpos d to 400 ppm of CO, IT MUST ALARM BETWEEN 
4 and 15 MINUTES.
• If th  alarm is  xpos d to 150 ppm of CO, IT MUST ALARM BETWEEN 
10 and 50 MINUTES.
•If th  alarm is  xpos d to 70 ppm of CO, IT MUST ALARM BETWEEN 
60 and 240 MINUTES.
*Approximat ly 10% COHb  xposur  at l v ls of 10% to 95% R lativ 
Humidity (RH).
Th  unit is d sign d not to alarm wh n  xpos d to a constant l v l 
of 30 ppm for 30 days.
CO Alarms ar  d sign d to alarm b for  th r  is an imm diat  lif  thr at.
Sinc  you cannot s  or sm ll CO, n v r assum  it’s not pr s nt.
•An  xposur  to 100 ppm of CO for 20 minut s may not aff ct av rag ,
halthy adults, but aft r 4 hours th  sam  l v l may caus  h adach s.
•An  xposur  to 400 ppm of CO may caus  h adach s in av rag , h althy
adults aft r 35 minut s, but can caus  d ath aft r 2 hours.
This CO Alarm m asur s  xposur  to CO ov r tim . It alarms if CO l v ls 
ar   xtr m ly high in a short p riod of tim , or if CO l v ls r ach a c rtain
minimum ov r a long p riod of tim . Th  CO Alarm g n rally sounds an alarm
bfor  th  ons t of symptoms in av rag , h althy adults.
Why is this important? B caus  you n d to b  warn d of a pot ntial CO 
probl m whil  you can still r act in tim . In many r port d cas s of CO 
 xposur , victims may b  awar  that th y ar  not f ling w ll, but b com  
disori nt d and can no long r r act w ll  nough to  xit th  building or g t
h lp. Also, young childr n and p ts may b  th  first aff ct d. Th  av rag 
h althy adult might not f l any symptoms wh n th  CO Alarm sounds.
How v r, p opl  with cardiac or r spiratory probl ms, infants, unborn babi s,
pr gnant moth rs, or  ld rly p opl  can b  mor  quickly and s v r ly aff ct d
by CO. If you  xp ri nc   v n mild symptoms of CO poisoning, consult your
doctor imm diat ly!
Standards: Und rwrit rs Laboratori s Inc. Singl  and Multipl  Station carbon
monoxid  alarms UL2034.
According to Und rwrit rs Laboratori s Inc. UL2034, S ction 1-1.2: “Carbon
monoxid  alarms cov r d by th s  r quir m nts ar  int nd d to r spond to
th  pr s nc  of carbon monoxid  from sourc s such as, but not limit d to,
 xhaust from int rnal-combustion  ngin s, abnormal op ration of fu l-fir d
applianc s, and fir plac s. CO Alarms ar  int nd d to alarm at carbon
monoxid  l v ls b low thos  that could caus  a loss of ability to r act to th 
dang rs of Carbon Monoxid   xposur .” This CO Alarm monitors th  air at
th  Alarm, and is d sign d to alarm b for  CO l v ls b com  lif  thr at ning.
This allows you pr cious tim  to l av  th  hous  and corr ct th  probl m.
This is only possibl  if Alarms ar  locat d, install d, and maintain d as
dscrib d in this manual.
Gas Detection at Typical Temperature and Humidity Ranges: Th  CO Alarm
is not formulat d to d t ct CO l v ls b low 30 ppm typically. UL t st d for
fals  alarm r sistanc  to M than  (500 ppm), Butan  (300 ppm), H ptan 
(500 ppm), Ethyl Ac tat  (200 ppm), Isopropyl Alcohol (200 ppm) and Carbon
Dioxid  (5000 ppm). Valu s m asur  gas and vapor conc ntrations in parts
p r million.
Audible Alarm: 85 dB minimum at 10 f t (3 m t rs).
TESTING & MAINTENANCE
WEEKLY TESTING
• Test the CO Alarm once a week. If the CO Alarm ever fails to test 
correctly, have it replaced immediately! If the CO Alarm is not working
properly, it cannot alert you to a problem.
• DO NOT stand close to the Alarm when the horn is sounding.
Exposure at close range may be harmful to your hearing. When 
testing, step away when horn starts sounding.
Push and hold th  T st/Sil nc  button on th  cov r until th  LED flash s. Th 
alarm horn will sound 4 b ps, a paus , th n 4 b ps. Th  ALARM (RED) light
will flash.
Th  alarm s qu nc  should last 5-6 s conds. If it do s not alarm, mak  sur 
fr sh batt ri s ar  corr ctly install d, and t st it again. If th  unit still do s not
alarm, r plac  it imm diat ly.
If the alarm does not test properly:
1. Mak  sur  th  batt ry is install d corr ctly.
2. B  sur  th  Alarm is cl an and dust-fr .
3. Install a fr sh 9V batt ry*and t st th  Alarm again.
• DO NOT try fixing the Alarm yourself   this will void your warranty! 
If the CO Alarm is still not operating properly, and it is still under 
warranty, please see "How to Obtain Warranty Service" in the Limited
Warranty. Install a new CO Alarm immediately.
• The Test/Silence button is the only proper way to test the CO Alarm.
NEVER use vehicle exhaust! Exhaust may cause permanent damage
and voids your warranty.
*For a list of acc ptabl  r plac m nt batt ri s, s  “R gular Maint nanc .”
REGULAR MAINTENANCE
To keep the CO Alarm in good working order:
• T st it  v ry w k using th  T st/Sil nc  button.
•Vacuum th  CO Alarm cov r onc  a month, using th  soft brush attach-
mnt. N v r us  wat r, cl an rs, or solv nts, sinc  th s  may damag 
th  unit. T st th  CO Alarm again aft r vacuuming.
• R plac  th  batt ry wh n th  CO Alarm “chirps” about  v ry minut  (th 
low batt ry warning).
Th  low batt ry warning should last for 30 days, but you should r plac  th 
batt ry imm diat ly to continu  your prot ction.
Choosing a replacement battery:
This CO Alarm r quir s on  9V alkalin  batt ry. Th  following batt ri s ar 
acc ptabl  as r plac m nts: Alkalin  Batt ri s — Durac ll MN1604 or
En rgiz r 522; Lithium Batt ri s — Ultralif  U9VL-J, U9VL-J-P. Th s 
r plac m nt batt ri s ar  commonly availabl  at local r tail stor s.
Us  only th  r plac m nt batt ri s list d. Th  unit may not op rat  prop rly
with oth r batt ri s. N v r us  r charg abl  batt ri s sinc  th y may not 
provid  a constant charg .
DO NOT spray cleaning chemicals or insect sprays directly on or near
the CO Alarm. DO NOT paint over the CO Alarm. Doing so may cause
permanent damage.
Hous hold cl an rs, a rosol ch micals, and oth r contaminants can aff ct
th  s nsor. Wh n using any of th s  mat rials n ar th  CO Alarm, mak  sur 
th  room is w ll v ntilat d.
This CO Alarm is intended for residential use. It is not intended for 
use in industrial applications where Occupational Safety and Health
Administration (OSHA) requirements for carbon monoxide detectors
must be met.
CO Alarms may not waken all individuals. If childr n or oth rs do not r adily
wak n to th  sound of th  CO Alarm, or if th r  ar  infants or family m mb rs
with mobility limitations, mak  sur  that som on  is assign d to assist th m
in th   v nt of an  m rg ncy.
CO Alarms will not work without power. This alarm r quir s a 9V alkalin 
batt ry to op rat .
CO Alarms for Solar or Wind Energy users and battery backup power
systems: AC pow r d CO Alarms should only b  op rat d with tru  or pur 
sin  wav  inv rt rs. Op rating this Alarm with most batt ry-pow r d UPS
(unint rruptibl  pow r supply) products or squar  wav  or “quasi sin  wav ”
inv rt rs will damage the Alarm. If you ar  not sur  about your inv rt r or
UPS typ , pl as  consult with th  manufactur r to v rify.
This CO Alarm will not sense carbon monoxide that does not reach the
sensor. This CO Alarm will only s ns  CO at th  s nsor. CO may b  pr s nt 
in oth r ar as. Doors or oth r obstructions may aff ct th  rat  at which CO
rach s th  CO Alarm. For this r ason, if b droom doors ar  usually clos d 
at night, w  r comm nd you install a CO Alarm in  ach b droom and in th 
hallway b tw n th m.
CO Alarms may not sense CO on another level of the home. For  xampl ,
a CO Alarm on th  s cond l v l, n ar th  b drooms, may not s ns  CO in th 
bas m nt. For this r ason, on  CO Alarm may not giv  ad quat  warning.
Compl t  cov rag  is r comm nd d. Plac  CO Alarms on  ach l v l of th 
hom .
CO Alarms may not be heard. Th  alarm horn loudn ss m ts or  xc ds
curr nt UL standards of 85 dB at 10 f t (3 m t rs). How v r, if th  CO Alarm
is install d outsid  th  b droom, it may not wak  up a sound sl p r or on 
who has r c ntly us d drugs or has b n drinking alcoholic b v rag s. This 
is  sp cially tru  if th  door is clos d or only partly op n. Ev n p rsons who
ar  awak  may not h ar th  alarm horn if th  sound is block d by distanc  or
clos d doors. Nois  from traffic, st r o, radio, t l vision, air condition r, or
oth r applianc s may also pr v nt al rt p rsons from h aring th  alarm horn.
This CO Alarm is not int nd d for p opl  who ar  h aring impair d.
CO Alarms are not a substitute for a smoke alarm. Although fir  is a
sourc  of carbon monoxid , this CO Alarm do s not s ns  smok  or fir . This
CO Alarm s ns s CO that may b   scaping unnotic d from malfunctioning 
furnac s, applianc s, or oth r sourc s. Early warning of fir  r quir s th  
installation of smok  alarms.
CO Alarms are not a substitute for life insurance. Though th s  CO Alarms
warn against incr asing CO l v ls, BRK Brands, Inc. do s not warrant or imply
in any way that th y will prot ct liv s from CO poisoning. Hom own rs and
r nt rs must still insur  th ir liv s.
CO Alarms have a limited life. Although th  CO Alarm and all of its parts
hav  pass d many string nt t sts and ar  d sign d to b  as r liabl  as 
possibl , any of th s  parts could fail at any tim . Th r for , you must t st
your CO Alarm w kly.
CO Alarms are not foolproof. Lik  all oth r  l ctronic d vic s, CO Alarms
hav  limitations. Th y can only d t ct CO that r ach s th ir s nsors. Th y
may not giv   arly warning to rising CO l v ls if th  CO is coming from a
rmot  part of th  hom , away from th  CO Alarm.
TROUBLESHOOTING GUIDE
CO Alarm sounds fr qu ntly  v n though no high 
l v ls of CO ar  r v al d in an inv stigation. Th  CO Alarm may b  improp rly locat d. R f r to
“Wh r  to Install CO Alarms.” R locat  your alarm. If fr qu nt alarms continu , 
hav  hom  r ch ck d for pot ntial CO probl ms. 
You may b   xp ri ncing an int rmitt nt CO probl m.
Th  light flash s (RED) and th  horn sounds 
5 “chirps”  v ry minut . END OF LIFE SIGNAL. CO Alarm n ds to b 
r plac d. Imm diat ly r plac  th  CO Alarm.
If you hav  any qu stions that cannot b  answ r d by r ading this manual, call Consum r Affairs at 1-800-323-9005.
“ALARM-MOVE TO FRESH AIR”
If you hear the alarm horn and the Red light is flashing, 
move everyone to a source of fresh air. 
DO NOT disconnect the battery from the CO Alarm!
Fuel-burning appliances like: portabl  h at r, gas or wood burning fir plac ,
gas kitch n rang  or cooktop, gas cloth s dry r.
Damaged or insufficient venting: corrod d or disconn ct d wat r h at r
v nt pip , l aking chimn y pip  or flu , or crack d h at  xchang r, block d
or clogg d chimn y op ning.
Improper use of appliance/device: op rating a barb cu  grill or v hicl  in
an  nclos d ar a (lik  a garag  or scr n d porch).
Transient CO Problems: “transi nt” or on-again-off-again CO probl ms can
b caus d by outdoor conditions and oth r sp cial circumstanc s.
*For a list of acc ptabl  r plac m nt batt ri s, s  “Pag  4: R gular Maint nanc .”
GENERAL LIMITATIONS OF CO ALARMS
The following conditions can result in transient CO situations:
1. Exc ssiv  spillag  or r v rs  v nting of fu l applianc s caus d by outdoor
conditions such as:
• Wind dir ction and/or v locity, including high, gusty winds. H avy air in
th  v nt pip s (cold/humid air with  xt nd d p riods b tw n cycl s).
• N gativ  pr ssur  diff r ntial r sulting from th  us  of  xhaust fans.
• S v ral applianc s running at th  sam  tim  comp ting for limit d 
fr sh air.
• V nt pip  conn ctions vibrating loos  from cloth s dry rs, furnac s, or
wat r h at rs.
• Obstructions in or unconv ntional v nt pip  d signs which can amplify
th  abov  situations.
2. Ext nd d op ration of unv nt d fu l burning d vic s (rang , ov n, 
fir plac ).
3. T mp ratur  inv rsions, which can trap  xhaust clos  to th  ground.
4. Car idling in an op n or clos d attach d garag , or n ar a hom .
Th s  conditions ar  dang rous b caus  th y can trap  xhaust in your 
hom . Sinc  th s  conditions can com  and go, th y ar  also hard to 
rcr at  during a CO inv stigation.
POTENTIAL SOURCES OF CO IN THE HOME
REGULATORY INFORMATION FOR CO ALARMS
First Al rt®is a r gist r d trad mark of th  First Al rt Trust. Print d in M xico   M08-0217-008   P02/12
IMPORTANT! PLEASE READ CAREFULLY AND SAVE.
This us r’s manual contains important information about your Carbon
Monoxid  Alarm’s op ration. If you ar  installing this CO Alarm for us  by
oth rs, you must l av  this manual—or a copy of it—with th   nd us r.
M08-0217-008   P02/12   Print d in M xico
BATTERY POWERED 
CARBON MONOXIDE ALARM
USER’S MANUAL
LISTED TO 
UL 2034
STANDARD
Model CO250
WITH TAMPERPROOF BRACKET AND 5-YEAR LITHIUM BATTERY
HOW TO INSTALL THIS TAMPERPROOF CO ALARM
THE PARTS OF THIS ALARM
FOLLOW THESE SIMPLE STEPS!
1. “OPEN HERE” tab
2. Cov r hing 
3. T st/Sil nc  button
4. Pow r/alarm indicator
Tools you will need:
• P ncil • Drill with 3/16” (5 mm) drill bit
• Hamm r • Scr wdriv r that acc pts standard driv r bits
Prepare Alarm for activation
1. Hold bas  firmly and pull up on cov r tab mark d “OPEN HERE.” This
will op n th  hing d cov r. Th  cov r may unsnap from th  bas  if it's
op n d too far. This will not damag  th  unit—th  cov r hing  snaps
back into plac   asily.
2. Activat  th  batt ry. With th  cov r op n, r mov  th  plastic “Batt ry
Pull Tab”. Your alarm is now activat d.
Onc  th  batt ry is install d, th  r d pow r indicator light (b hind th 
t st button) will flash onc  a minut  to show you th  CO Alarm is 
working.
3. Clos  th  cov r all th  way.
To replace the battery, r install a n w on  so th  t rminals on th  batt ry
match th  t rminals on th  CO Alarm. Match “+” to “+” and “-” to “-.”
Push th  batt ry in until it snaps in s cur ly and cannot b  shak n loos .
If th  batt ry is not snapp d in compl t ly, th  unit cannot r c iv  batt ry
pow r. Th  CO Alarm may b p bri fly wh n you install th  batt ry—this 
is normal.
Install the Alarm Locking Pin
1. Using n dl -nos  pli rs or a utility knif , d tach locking pin from back of
alarm bas .
2. Ins rt locking pin into th  slot locat d on th  front of th  alarm as shown in
th  diagram.
To unlock th  cov r to th  bas , r mov  pin to unlock and r plac  batt ry
wh n r quir d. R -install th  locking pin.
Cover Open
1. “Op n H r ”
2. T st/Sil nc  button
3. CO alarm bas 
4. “No Batt ry” tab
5. Mounting slots
6. Install 9V batt ry h r 
7. Locking pin slot
IF YOUR CO ALARM SOUNDS
Actuation of your CO Alarm indicates the presence of carbon monoxide
(CO) which can kill you. In other words, when your CO Alarm sounds, 
you must not ignore it!
IF THE ALARM SIGNAL SOUNDS:
1. Op rat  th  T st/Sil nc  button.
2. Call your  m rg ncy s rvic s, fir  d partm nt or 911. Writ  down th  
numb r of your local  m rg ncy s rvic  h r :
_________________________________________________________________
3. Imm diat ly mov  to fr sh air—outdoors or by an op n door or window.
Do a h ad count to ch ck that all p rsons ar  account d for. Do not r -
 nt r th  pr mis s, or mov  away from th  op n door or window until th 
 m rg ncy s rvic s r spond r has arriv d, th  pr mis s hav  b n air d
out, and your CO Alarm r mains in its normal condition.
4. Aft r following st ps 1-3, if your CO Alarm r activat s within a 24-hour
p riod, r p at st ps 1-3 and call a qualifi d applianc  t chnician to
inv stigat  for sourc s of CO from fu l-burning  quipm nt and applianc s,
and insp ct for prop r op ration of this  quipm nt. If probl ms ar  
id ntifi d during this insp ction hav  th   quipm nt s rvic d imm diat ly.
Not  any combustion  quipm nt not insp ct d by th  t chnician, and
consult th  manufactur rs’ instructions, or contact th  manufactur rs
dir ctly, for mor  information about CO saf ty and this  quipm nt. Mak 
sur  that motor v hicl s ar  not, and hav  not, b n op rating in an
attach d garag  or adjac nt to th  r sid nc . Writ  down th  numb r 
of a qualifi d applianc  t chnician h r :
_________________________________________________________________
SILENCING THE LOW BATTERY WARNING
This sil nc  f atur  can t mporarily qui t th  low batt ry warning “chirp” for
up to 8 hours. You can sil nc  th  low batt ry warning “chirp” by pr ssing 
th  T st/Sil nc  button. Th  horn will chirp, acknowl dging that th  low 
batt ry sil nc  f atur  has b n activat d.
Aft r 8 hours, th  low batt ry “chirp” will r sum . Replace the battery as
soon as possible; this unit will not operate without battery power!
To deactivate this feature: Pr ss th  T st/Sil nc  button again. Th  unit will
go into T st Mod  and th  low batt ry warning will r sum  (LED flash s and
unit sounds “chirp” onc  a minut .)
If you cannot silence the low battery warning, replace the battery 
immediately.
SILENCING THE END OF LIFE SIGNAL
This sil nc  f atur  can t mporarily qui t th  End of Lif  warning “chirp” for
up to 2 days. You can sil nc  th  End of Lif  warning “chirp” by pr ssing th 
T st/Sil nc  button. Th  horn will chirp, acknowl dging that th  End of Lif 
sil nc  f atur  has b n activat d.
Aft r approximat ly 2 days, th  End of Lif  “chirp” will r sum . 
Aft r approximat ly 2-3 w ks th  End of Lif  warning cannot b  sil nc d.
Install the Tamperproof Bracket
1. Hold th  tamp rproof brack t against th  c iling (or wall) and mak  a mark at th  c nt r of  ach of th  thr  mounting
hol s with a p ncil. (Not : For wall mounting, mak  sur  th  arrows point up and th  tab fac s l ft. S  illustration.)
2. Put th  unit wh r  it won’t g t cov r d with dust wh n you drill th  mounting hol s.
3. Using a 3/16” (5 mm) drill bit, drill a hol  through  ach p ncil mark.
4. Ins rt th  plastic scr w anchors (in th  plastic bag with scr ws) into th  hol s. Tap th  scr w anchors g ntly with a
hamm r, if n c ssary, until th y ar  flush with th  c iling or wall.
5. Th r  ar  two typ s of scr ws provid d. Two standard scr ws for mounting hol s “A” and on  tamp rproof scr w for
mounting hol  “B”. At this point only install and tight n th  scr ws into th  scr w anchors for th  two standard scr w
hol s (“A”). Do not install th  tamp rproof scr w y t.
Install the CO Alarm onto the Tamperproof Mounting Bracket
1. Mak  sur  alarm is position d as shown. Th  words “CARBON MONOXIDE ALARM” should b  r adabl  
lft to right.
2. Lin  up th  mounting slots on th  back of th  alarm and mat  with th  mounting tabs on th  
Tamp rproof Brack t. Push down and slid  alarm to th  right to lock in position.
3. Install th  Tamp rproof Locking Ring by sliding th  pins into hol s on th  brack t. Install th  
tamp rproof scr w (#6-32x1 Spann r Scr w) through th  Locking Ring and Mounting Brack t 
and tight n with th  suppli d tamp rproof scr w bit (#6 spann r bit).
4. T st th  CO Alarm. S  “W kly T sting.”
5. K p tamp rproof scr w bit in a saf  location. You will n d it to r mov  th  alarm to chang  th  batt ry.
A
B