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False Fire Alarms - common causes and how to avoid them

In this article we review some of the most common causes of false fire alarms and how to avoid them. It covers:

  1. What is a false fire alarm
  2. Explanation of the various types of fire detectors
  3. Selecting equipment that is fit for purpose
  4. Maintenance guidelines
  5. Training and educating users

There is a common misconception between what is classed as a ‘false’ fire alarm and an ‘unwanted’ fire alarm activation, so firstly, we need to differentiate between ‘false’ fire alarms and an ‘unwanted’ fire alarm.

An alarm which sounds because a toaster has activated a smoke detector is an unwanted alarm. This is because the alarm has done its job. It has genuinely detected smoke and has activated to warn that there may be a fire. A false fire alarm is where no explanation can be given as too why the detector has activated, requiring further investigation by the fire alarm maintenance company.

A smoke detector which activates when there is no fire is at best likely to cause an annoying unwanted fire alarm activation. At worst such a malfunction could cause significant disruption to employees, visitors and members of the public. Overall, a smoke detector alarming repeatedly when there is no fire will make people lose confidence and could compromise health and safety.

In 2014, The Building Research Establishment (BRE) conducted a research exercise into the causes of false fire alarms. They listed over 30 common causes, which can be grouped further under the following key headings:

  • Manual Call Point (MCP) accidentally activated
  • Dust
  • Old detectors
  • Equipment faults
  • Cooking
  • Water or steam

In the majority of the above cases the following changes helped to remedy the number and occurrence of false alarms.

Multi sensor fire detectors

The single most effective method to avoiding such instances is to choose the type and location of detection device carefully and with expert assistance.

Multi-sensor detectors have the added advantages of providing greater confidence of a fire condition by detecting more than one fire signature and increasing sensitivity levels when more than one fire signature is present which ensures a quicker alarm response. Whilst it can be expensive to replace all detectors, it can be very cost effective to replace those in problems areas.

When replacing detectors, consideration should also be given to the best location considering local (potentially changing) false alarm sources.

Covered Manual Call Points (MCP)

Sometimes the MCP can be mistaken for the building exit button, and sometimes pranksters think activating a fire alarm is a fun thing to do.  Malicious or accidental triggering of the fire alarm can be remedied by fitting covers to the MCP’s. Lifting the cover causes the user to focus more on what they are doing and helps to draw their attention to the fact that they are about to lift the cover on a fire alarm activation point.

Fire equipment choice and maintenance

Selecting fire alarm equipment that is fit for purpose in relation to the location within the premises it is intend to protect is a vital first step. Once installed, regular inspection and testing is key and will help to reduce false fire alarms because equipment will be cleaned and checked to identify potential problems, and defective parts can replaced before they cause an unwanted activation.

The use of an of EN 54-2 approved analogue addressable control panel will also help, as it will perform three principal functions:

  • Automatic monitoring and control of circuits external to the equipment, such as fire detection and fire alarm device circuits and supply of power to these circuits
  • Indication of fire signals, fault signals and their location
  • Manual control to facilitate actions such as testing, disablement of devices, triggering of fire signals, silencing of audible fire warnings and resetting the system after a fire signal

It is important to always record the time and date as well as the location, zone and devices that have activated as this valuable information helps to identify trends and further reduce false alarms. This is very valuable information for your maintenance engineer as it will help direct his investigation into the exact cause.

Fire safety training and education

Assuming that the appropriate equipment has been chosen and detectors are installed in the right places, there is no doubt that training and education helps to reduce false fire alarms. Whether these be formal training sessions or educative notices, ensuring building occupants have knowledge of the kind of activities that will cause a false alarm will play a vital part in reducing the number of false alarms you experience.


Posted on: 20 February 2017
Posted in: News