Specifications

6
This will depend on a number of factors that will differ slightly according to the type of alarm
in use.
The 140 series alarms are supplied with an Alkaline battery which, dependent on conditions, can
provide up to 4 years standby supply, up to 2 years without mains power.
The 150 series and the 160 series alarms are fitted with rechargeable Lithium power cells which are
continuously charged by the alarm circuitry. They have a life expectancy greater than that of the
Smoke Alarm, i.e 10 years or more, which eliminates the need for replacement.
If either, the voltage of the battery falls to a sufficiently low level, the internal resistance of the
battery reaches a predetermined state, the alarm unit will emit a warning beep every 40 seconds.
In the case of the 140 series alarms, it is probable that the alkaline battery in the unit requires
replacement. Access to the battery is gained by removing the alarm from the Easi-fit mounting
plate. The power cells on the 150 and 160 series alarms are not replaceable. If these units emit a
low battery warning beep it is probable that the mains supply has failed. The cables, fuses etc should
be investigated and the fault rectified. If the beeping continues the alarm may have a fault and it
should be returned for inspection.
MISCELLANEOUS
There is no technical reason why a Smoke or Heat Alarm should not last more than 10 years,
but the actual lifespan will depend to a large extent on where and how the alarm has been
sited, installed and maintained. The most common cause of alarm failure is due to
contamination of the sensor chamber and/or electronics. In certain circumstances, even with
regular cleaning, contamination can build up in the smoke sensing chamber causing the alarm
to sound. If this happens the alarm must be returned for servicing or repair. All manufacturers
of smoke alarms recommend that their products are replaced after 10 years use.
False alarms are usually a result of incorrect siting of the Smoke Alarm, or by contamination as a
result of building/redecoration operations, or by poor levels of maintenance. For instance, if
ionisation alarms are sited too close to a Kitchen, false alarm will often result due to invisible
cooking fumes reaching the alarm. Optical alarms are liable to contamination from dust and fibres,
often associated with building work being undertaken without the alarms being properly covered.
The 140, 150 and 160 series alarms are supplied with a 'hush button' that can be pressed to
desensitise them to allow time for the source of the problem to be investigated. Use of the 'hush
button' will only silence the alarm for 8 - 10 minutes after which the alarm will automatically reset.
If the cause of the false alarm is contamination, the only method of permanently silencing the alarm
is to remove the contamination source. This may not be possible without removal and cleaning of the
alarm. It can be difficult to reach the 'hush button' in some instances, particularly for the elderly
and infirm, so the installation of a wall mounted Remote Test and Hush Switch Ei152 with Ei166R,
Ei164R or Ei166R alarms could be considered to overcome this problem.
21. How long will
the battery last?
22. How will I know
if the battery
has failed?
23. How long do
Smoke Alarms
last?
24. How do I
stop false
alarms?