Significant differences between smoke alarms and user manuals

Stress tests of smoke alarms by the Finnish National Rescue Association SPEK found that smoke alarms and their user manuals differ significantly. When purchasing smoke alarms for housing companies, it is a good idea to carefully review the alarm’s user manual. For example, there may be differences in the reported battery life and testing procedure between the user manual and the label on the packaging.

“It is possible that the battery included with the alarm has expired before use, or that the user manual reports a different battery life than the text on the packaging, says Lauri Lehto, Fire Protection Technology Specialist at SPEK.

“In the stress tests, after a test period of one year, the battery of one of the tested smoke alarms only had enough power for a short alarm tone before quieting down entirely,” Lehto says.

In order for the smoke alarm to detect smoke sufficiently quickly, the alarm is recommended to be replaced every 5 to 10 years. The stress tests confirm this rule of thumb.

In SPEK’s stress tests, unused batteries from smoke alarm packages were stored in conditions that ranged from damp and cold to normal room conditions. After the test period, the batteries’ charge was tested.

Smoke alarms were put under stress in humid and normal room conditions. Their operation was tested monthly and the alarms’ sensitivity was measured after the test period.

Smoke alarms require regular maintenance

“Based on the stress tests, it can be said that the functioning of smoke alarms is ensured with regular maintenance. This includes testing the alarm periodically, replacing batteries and replacing an old alarm with a new one,” Lehto says.

Checking whether the alarm is audible and functional is done by pressing the test button. This also confirmst hat the batteries in a battery-powered smoke alarm have sufficient power.

“Housing companies should read the alarm’s instructions manual before purchasing to know what they are buying. This also allows better planning of maintenance measures and instructions for residents,” says Lehto.

In Finland as of the start of 2026, the property owner, such as a housing company, is responsible for ensuring that apartments are equipped with smoke alarms. Even after this, residents should continue to test smoke alarms regularly and report any problems.

When purchasing smoke alarms, consider where they will be placed, how easy the alarms are to use and what are their technical properties. Without careful planning, the alarm may prove to be unsuitable for the task and require replacement sooner than expected, resulting in increased costs.