How Do I Maintain My Smoke Detector?

So, your building has a smoke detector in it and you are wondering what is required as far as inspection, testing, and maintenance (ITM) to ensure that it is kept in working order to keep the occupants safe and protect your property.  Lets spend a few minutes going over some of the major requirements. 

Smoke Alarm vs. Smoke Detector

Before we start talking about maintaining a smoke detector, I first want to talk about the difference between a smoke alarm and a smoke detector. In the 2019 edition of NFPA 72, National Fire Alarm and Signaling Code, a smoke alarm is referred to as a single station or multiple station alarm that is responsive to smoke while a smoke detector, or any detector for that matter is a device that is connected to a circuit that has a sensor that responds to a physical stimulus such as heat or smoke.

So, what does that mean? Basically, is means that a smoke alarm is a self-contained unit that contains the sensor that is constantly monitoring for smoke and the audible alarm that activates to warn the occupants if smoke is detected.  A smoke detector on the other hand must be part of an fire alarm system because it can only send a signal back to the fire alarm control unit via a circuit if it detects smoke. Then, based on the programing, the fire alarm control unit may activate the audible notification for the occupants to evacuate and send a signal to a constantly attended location.

 Smoke alarms are required to be installed by NFPA 101, The Life Safety Code in such occupancies as daycares and residential, including one- and two-family dwelling units. You are more likely to see a full fire alarm system including smoke detectors in commercial occupancies such as business, assembly, and mercantile.

If you are looking for the ITM requirements for a smoke alarm, Chapter 14 of NFPA 72 requires them to be maintained in accordance with the manufacturer's instructions (typically cleaned with compressed air or a vacuum) and to be tested at least monthly. NFPA 72 also permits the ITM of the smoke alarms to be completed by the occupant of the dwelling unit.

Who Can Perform Smoke Detector ITM?

According to NFPA 72, The Fire Alarm Code, the property owner is ultimately responsible for ensuring that ITM is completed on the fire alarm system, including the smoke detectors. The property owner is permitted to delegate this responsibility to the building occupant or a management firm or individual if the authority having jurisdiction is notified.

The person performing the inspection testing and maintenance must be qualified per the authority having jurisdiction. This could include factory training for the brand being serviced, obtaining a nationally recognized certification, a person who is registered, licensed, or certified, or a person working for a company that is listed by a nationally recognized testing laboratory.

What Needs to Be Done?

Chapter 14 of NFPA 72 addresses Inspection, Testing, and Maintenance (ITM). Smoke detectors need to be

  • Inspected Semiannually
  • Functionally Tested Annually
  • Sensitivity Tested 1 year after install then checked every other year and increased to every 5 years if the device remains within its sensitivity range
  • Maintained in accordance with manufacturer's instructions

An inspection only means that you are visually confirming that the smoke detector looks like it will be able to operate. This includes checking for physical damage to the detector and making sure that the detector is not dirty or obstructed in a way to limit smoke being able to enter the sensing chamber. Some common obstructions include leaving the bright orange shipping cap on the detector or taping the detectors sensing chamber, both will render the detector inoperable.


Smoke Detector with Shipping Cap Still Installed

Smoke detectors need to be functionally tested annually to ensure there is an alarm response when smoke is introduced into the chamber. This means that artificial smoke needs to be used to make sure the smoke detectors are working properly, the use of a magnet to test a smoke detector is not an acceptable functional test because it only tests the circuitry and does not ensure that smoke entering the chamber will trigger a response. If you have the testing completed by a contractor you should work with them to ensure that their annual functional test includes the introduction of smoke and not a magnet.

Sensitivity testing needs to be completed to ensure that the smoke detector will send an alarm signal when a specific amount of smoke is introduced into the chamber. This is tested by using test equipment to introduce a known amount of smoke and checking to see when the detector goes into alarm. This needs to be done one year after installation and then every other year, if the detector remains within its listed and marked sensitivity, the testing can be completed every 5 years. Modern fire alarm equipment has the ability to monitor the sensitivity of all of the detectors constantly and in turn are not required to have sensitivity testing completed. If you have any question regarding whether your detectors require sensitivity testing, it is best to have a qualified person look at your system.

Maintenance on the smoke detectors needs to be completed per the manufacturer's instructions, this includes vacuuming or using compressed air to clean the chamber as needed based on the ambient conditions. Finally, it is very important that all records of inspection, testing, and maintenance be completed and maintained for at least one year.

Let me know in the comments below if you would be interested in some more fire alarm ITM, if so, what do you want to hear more about?

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Shawn Mahoney
Technical Services Engineer with a masters degree and PE in fire protection supporting subjects throughout the association

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