Part six – frequently asked questions – Nighthawk KN-COPP-3 User Manual
Part Six – Frequently Asked Questions
Q. How many alarms do I need in my house? How much
square footage will one alarm cover?
A. We recommend you place alarms near the sleeping area(s). If
you have a multi-level home, you should place an alarm on each
level of the home. A good rule of thumb for the number and
placement of CO alarms for your particular home is to place CO
alarms near smoke alarms that have been installed to meet cur-
rent building code requirements.
Generally, one alarm can be adequate for 1,200 to 1,500 square
feet of living space. The most important determination for the
number of units needed is whether an alarm can be heard in all
Q. Can you explain what “time-weighted alarm” means?
A. Because carbon monoxide is a cumulative poison, two factors
determine how the body is affected by CO: the level of exposure
and the length of exposure. For example, being continuously
exposed to low levels of carbon monoxide for many hours can
be as dangerous as being exposed to higher levels of CO for a
short period of time.
The microchip inside your Nighthawk CO alarm monitors the air
for the presence of carbon monoxide and computes the levels
and length of exposure, alarming when you should be con-
cerned about CO exposure.
For more information about the alarm, see page 5-1.
Q. Do I have to press the test button to get a CO reading?
A. No. Your Nighthawk CO alarm continuously monitors the air
for carbon monoxide. An updated reading is shown on the dig-
ital display every 15 seconds. If there is no CO present, the dig-
ital display will show a zero. The alarm will alert you to the pres-
ence of CO automatically.
To test the internal components and circuitry of your alarm, press
the Test/Reset button. For complete instructions on testing your
alarm, see page 1-5,6.
Q. What happens if the power goes out?
A. If a good battery is in the unit, the alarm will display a blink-
ing dot at least 20 hours while still providing protection against
CO exposure. Please see page 1-5.
Q. How do I get the alarm to show something besides “0.”
OR, How can I determine if the sensor is operating
A. Please refer to “Testing Sensor Response” on page 1-6 for com-
plete instructions on how to test your alarm’s electronics and sen-
Q. You warranty the alarm for five years. How will I know
when it doesn’t work anymore and I need to buy a new one?
A. In any event of malfunction, your alarm will alert you with
malfunction signals. These signals are described in detail on page
Q. What do the numbers mean on the digital display when
I press the “Test/Reset” button?
A. The numbers you see when you press the Test/Reset button
are NOT a CO reading. This is a simulated reading the alarm dis-
plays as it tests its electronics. The numbers displayed when the
Test/Reset button is pushed should be between 100 to 400 (usu-
ally around 200).
Q. I called in someone to inspect my home for CO after my
unit alarmed, and he couldn’t find anything wrong. Why?
Does that mean this unit “false alarmed”?
A. No. Please read the information explaining why a CO prob-
lem can be difficult to diagnose on page 4-2. Also, please read
the information on page 1-6 to make sure you experienced an
alarm and not a malfunction alert.
Q. I tried to test the alarm (see below) and it still reads “0.”
– by running the car in the garage
– by holding it to the tailpipe of the car
– by putting it next to the furnace vent
A. DO NOT try to test your alarm by doing any of the above!
Testing the alarm using any of the methods listed above usually
does not yield satisfactory results and could in fact be dangerous.
To accurately test the alarm, please follow the guidelines given
on page 1-5,6.
Never operate a vehicle in a closed garage, as high levels of CO
can be built up in a short time. With an attached garage, dan-
gerous CO levels develop inside the home as well as within the
Attempting to test the sensor function by holding the alarm next
to a tailpipe or furnace vent may not cause a reading on the dis-
play because today’s vehicles emit very little CO once the engine
reaches operating temperature. Likewise, many of today’s high
efficiency furnaces emit very low levels of CO.
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