Q) What is the difference between an ionization alarm and a photoelectric
In general ionization alarms are quicker at detecting fast flaming fires that give
off little smoke. Where as photoelectric (optical) alarms are quicker at
detecting slow smoldering fires.
Kidde recommends, for maximum protection, that both ionization and
photoelectric smoke alarms be installed.
Q) My smoke alarm seems to have started to chirp at certain times during
the day or night, why could this be?
When the temperature drops the voltage to the battery reduces which will
cause the unit to chirp. As the temperature rises so the chirping will cease.
This behavior normally denotes that the battery needs to be changed but this
could also happen on cold nights when the house is unheated.
Q) Why is my smoke alarm chirping?
There are a couple of reasons a unit may chirp. If the battery is low the unit can
have a sporadic chirping at first but should settle down to a 30-40 second
interval, this chirp will continue for at least 7 days or until the battery is
replaced. The second cause for this chirp is if the alarm sensor has
malfunctioned, the alarm must be replaced in this case.
Q) The unit keeps chirping after I press the Hush button. What should I
The Hush button is designed when activated to chirp every 30-40 seconds for
The smoke alarm unit will automatically re-set and go quiet after 7 minutes
providing that the Hush button has not been pressed more than once. If you
have touched the Hush button more than once it will complete a further
7-minute cycle for each time the Hush has been pressed.
Q) How can I tell the difference between the malfunction chirp and the
low battery chirp?
When the unit malfunctions the red LED will flash between chirps, whereas the
red LED will flash in synch with the chirps for a low battery.
Q) Where should I locate my smoke alarm?
We would recommend that each household have a smoke alarm at each
level-one in the hallway and one at the top of the stairs. It would be even safer
to have an additional one in each bedroom.
Q) Where should smoke alarms not be fitted?
The locations to avoid when fitting any smoke alarms are as listed below.
- In the garage as products of combustion are present when the car is started.
- In kitchens
- In front of forced air ducts used for heating and air conditioning, near ceiling
fans or other high flow areas.
- In the peak of an ’A’ frame type ceiling.
- In an area where the temperature may fall below 40°F (4℃) or rise above
- In dusty areas. Dust particles may cause nuisance alarm or failure to alarm.
- In very humid areas or near a bathroom. Moisture or steam can cause
- Near fluorescent lights. Electronic ”noise” may cause nuisance alarms.
Interconnectable Smoke Alarms
Q) Can I interconnect my old kidde interconnectable smoke alarms with
the new interconnectable one I just purchased?
Yes, all the new kidde models have been made to facilitate this capability. If the
existing models are more than 7 years old it may be worth updating them also.
Q) My hard wired smoke alarm has a flashing green LED, does this mean
that it is malfunctioning?
No, what this means is that the unit has gone into an alarm. This is called the
alarm memory condition, and it will continue to flash until the reset button has
Q) Can I interconnect my hard wired Kidde units with other brands?
It is not advisable to do this because other manufacturing companies may use
a different temporal pattern (temporal pattern means how the voltage is sent
over the interconnect white wire that tells the other units to go off as the
originating smoke alarm has sensed some smoke).
Q)With interconnected smoke alarms if one unit starts to malfunction will
the others on the same circuit be affected?
If all the units are interconnected and one goes into an alarm or malfunction
state, it will cause the rest of the units to also signal that alarm or malfunction.
The originating smoke alarm will be the unit with the rapidly flashing red LED
while the unit is in alarm, or it will be the flashing green LED alarm memory
condition afterwards. Reset this unit and the problem should stop, if not then
disconnect the unit and diagnose the unit individually.
Q) I have just installed some hardwired smoke alarms but they are
chirping, why is this?
It is important when installing the smoke alarms to ensure that all the batteries
are in place and that smoke alarms are all correctly wired up otherwise they
will chirp. To check this each smoke alarm should have a permanent green led
If you install smoke alarm models with the hush button then it is very easy to
touch the hush and the alarm will then chirp every 30-40 seconds for 7 minutes
before going quiet. Each time the hush button has been touched will elicit a
7-minute chirp cycle.
Q) Can you tell me how your heat alarms work?
The temperature needs to rise to 57C before the detector will sound. It does
not matter how much smoke is being generated that is why heat detectors
should only be used in the kitchen with either an ionization or photo-electric
smoke alarm linked in the hallway.