Fire alarms and preventing false alarms

Fire alarms and preventing false alarms

More than one in every three incidents we respond to are false, or ‘unwanted’ alarms.

Unwanted alarms affect you and can be a risk to the lives of others because they divert resources away from real emergencies.

What is an unwanted or false fire alarm?

An unwanted alarm is a fire alarm (signal) resulting from a cause other than fire.  Any Automatic Fire Alarm (AFA) that we attend that is not actually a fire is considered to be an ‘unwanted’ alarm.

How false or unwanted alarms impact the fire service

  • Unwanted alarms divert the fire service away from attending real emergencies.
  • Responding to unwanted alarms creates unnecessary risk to fire crews and members of the public when fire engines are driven under ‘blue light’ conditions.
  • Occupants of buildings that have frequent unwanted alarms get used to them and may delay their response or worse - not respond at all - to a real emergency.
  • Unwanted alarms disrupt fire service prevention activities, arson reduction and training.
  • They cost the fire service money unnecessarily by sending vehicles and firefighters to attend.

How false alarms impact businesses

Every time the alarm sounds, everyone has to stop what they are doing and evacuate the building. This may prove to be very costly not only in productivity and financial terms, but also because staff will become complacent and will lose faith in the fire alarm system if they are constantly required to leave the building due to a false alarm.

How to prevent false alarms

You can prevent many unwanted alarms by being aware of the potential causes.

Common causes of false alarms in the workplace

Cooking fumes

  • Only cook in rooms intended for cooking.
  • If you can, use extractor fans, and close doors between designated cooking areas and your smoke alarm to further prevent false alarms.
  • Toasters often cause false alarms so carefully consider where these are placed.
  • You should not have a smoke alarm in a kitchen area - only heat alarms are suitable for a kitchen space. Wrongly-placed smoke alarms could cause frequent false alarms – and cause employees to start ignoring alarms. This can be very dangerous.

Steam - from showers or industrial processes


Ventilation is key to reducing false alarms caused by steam from showers. Closing doors can also help.

If your business uses industrial processes which produce steam, you should make sure you have an appropriate detector for that area. Speak to a qualified alarm engineer for advice.

Aerosol sprays and dust

  • Products such as deodorant and hair spray will commonly set off smoke detectors. Please avoid using them near smoke alarms, or use non-aerosol alternatives.
  • Dust and insects in detectors. Dusting or vacuuming your smoke detectors can help reduce false alarms caused by dust and insects.

Other common causes of false alarms

  • Smoking near the alarm.
  • Water in the alarm from flooding or leaks.
  • Controlled processes that produce smoke and fumes.
  • Contractors or work activities, including hot works.
    • Consider fitting temporary covers on detectors while the work is being carried out. Temporary covers should only be fitted by approved staff and removed immediately after the activity has ended. Whilst detectors are covered in this way, staff working in the area (including contractors) should be briefed to activate a 'break glass' call point if they see a fire. Dust can also prevent detectors from working effectively in the future. It is important to plan all hot and dusty work carefully.
  • Mechanical damage/disruption or faults.
  • Damaged or faulty fire and smoke detectors may result in repeated unexplained alarms. You should have the fire alarm system checked by a competent person as soon as possible.
  • Testing or maintenance of fire alarm systems without prior warning to the Alarm Receiving Centre (ARC). 
    • Before starting any testing or maintenance you must - if your system is monitored - inform your alarm centre that the testing and maintenance is taking place and inform them when it is completed.
  • Accidental or malicious alarms by activating ‘break glass’ call points.
    • There are ways to reduce the risks of break glass call point accidental or malicious alarms. Speak to your alarm engineer or maintenance contractor. If any changes are made, you must review your fire risk assessment.

Your legal obligations

If your premises have an automatic fire alarm (AFA) system, you are legally obliged to ensure that your building is suitably managed to avoid unwanted alarms.

Many false alarms can easily be identified by people at the premises and so do not require a call to us.

If you have unwanted alarms you are obliged to take appropriate steps to reduce them and record your actions.

We strongly recommend that where your alarm monitoring company passes a call to the fire service, designated key holders are also alerted at the same time as the initial call, and are requested to attend the site within 20 minutes.

If the fire service has been called and you discover it is a false alarm, call the fire service back (999) to confirm it is an unwanted alarm. This will allow fire service resources to be released for confirmed emergencies.

Please help us to reduce false or unwanted alarms.

Charges for false or unwanted alarms

We can recover costs from responsible persons for attendance by the fire and rescue service for repeated unwanted fire alarms.

See our standard charges.

False alarm stats
Last updated: 9.01am - 02 December 2023
False alarms in the last 12 months

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