NFPA 25: Sample Fire Sprinkler Testing

Sample fire sprinkler testing verifies functionality and performance to ensure heads properly activates in the event of a fire. NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems requires testing by a certified testing laboratory at specific intervals. The specific requirements of testing sprinklers are found in sub-sections 5.3.1 through (2017 edition). These sections provide the necessary information on how many samples are required, from where to take the samples, and how often each type of sprinkler is required to be sent for testing.

Requirements for fire sprinkler testing samples

fire sprinkler testing tag

Courtesy of UL

A sample must be at least four sprinklers or 1% of the sample area, whichever is greater. Keep in mind that there is subjectivity in the selection of representative sprinkler samples, which could apply to the entire building, the whole system, or a specific area. The annex section clarifies that sprinklers produced by the same manufacturer within a similar environment are permitted to be considered part of the same sample, but additional sprinklers would be included with the sample if produced by a different manufacturer. Since the test of the sprinkler is destructive, a new sprinkler will need to be installed in place of the removed sample.

fire sprinkler testing kit

Dyne Fire Protection Labs kit – Click the image to learn more!

Once removed, each sprinkler should have a tag attached (such as the example below) and packaged to prevent damage during shipping. UL will provide these tags free of charge; however, there is a fee for testing each sprinkler sample sent in.

Based on section, the sample area or groups of sprinklers can be determined by the inspector and/or the building owner. Keep in mind that sprinklers should be random from different floors and areas of the building—and not chosen because they are easier to access than other sprinklers.

Sample fire sprinkler testing: a scenario

To demonstrate the NFPA 25 requirement on sample fire sprinkler testing, we will use a five-story apartment building with 100 sprinklers per floor.

If the sample area were chosen by floor, you would be required to take a minimum of four sprinklers from each floor, which would be 20 total sprinklers. If the entire building were your sample area, you would be required to take 1% or five sprinklers as your sample. You can see the difference in sending out five sprinklers vs. 20 sprinklers for testing.

Consider section if one sprinkler fails, all sprinklers in that sample area must be replaced. In the example above, if the by-floor sample was used and one sprinkler failed on a floor, only the 100 sprinklers on that floor would require replacement. If the entire building sample was chosen and one sprinkler failed, then all 500 sprinklers in the building would require replacement. This information should be reviewed between the contractor and the building owner to discuss the benefits and drawbacks of different sampling areas and sizes.

Sprinkler failures are caused by, but not limited to, loading, internal and external corrosion, and paint (other than that applied by the manufacturer).

Do you have a question about sample fire sprinkler testing? NFSA members can reach out via our website or by calling 443-863-4464 for answers and support from our engineering, codes, and standards experts. Not an NFSA member yet? Join today!




For over a century, the National Fire Sprinkler Association (NFSA) has served as the voice of the fire sprinkler industry. Our mission: advocating to protect lives and property through the widespread acceptance of the fire sprinkler concept. To join NFSA or learn more about the ways membership can benefit your organization, visit