The 2017 Edition of the NFPA 25 Handbook

All fire sprinkler heads require regular inspection and very old, damaged, or otherwise impaired fire sprinklers must be replaced

Fire sprinklers are known for their longevity. In many cases, their lifespan can be comparable to the buildings in which they are found. But because fire sprinklers remain idle, it's often difficult to identify a problem.

Unless a problem is highly visible – like a leak or corrosion – it may go unnoticed for months or even years. This means in the case of an emergency, the system may not activate properly– or at all!

The only true way to identify a problem is by performing regular inspections, testing, and maintenance. However, if most of these are performed based on the age of the sprinklers, how can one tell the age of a fire sprinkler head? And once you know the age, how do you know when to test or replace a sprinkler head? In this article, we’ll help you find the answer to all of your most burning questions.

Need to replace your fire sprinkler heads right away? Feel free to jump on over and check out our selection of commercial fire sprinklers.

How do I determine the age of fire sprinklers in a system?

To determine the age of fire sprinklers in a system, begin by inspecting building documentation and other pertinent information. In the best-case scenario, there is a record of the building completion and system installation, renovations and/or upgrades, and the sprinklers within the system.

It has been common practice for the inspector to examine the supply of spare sprinkler heads in the fire sprinkler head replacement cabinet. The reasoning is that, in theory, these sprinklers are the same age as those installed in the system. However, if any spares have been used and replaced over the years, they may not match the age of those within the system. This is where it gets a bit tricky and why you should not rely on this method alone.

When do I perform a fire sprinkler inspection?

NFPA 25 requires professional fire sprinkler inspections on an annual basis. However, industry best practices suggest performing quarterly inspections as well.

A man inspects a fire sprinkler.

A man performs a visual inspection of a fire sprinkler head. Source: Cintas

From the 2016 Edition of NFPA 25 Sprinklers shall be inspected from the floor level annually.

Quarterly inspections apply mostly to facility managers and maintenance personnel. In conducting inspections, it’s best to form a routine and remain consistent. Over time it creates a familiarity with the system and makes it easy to spot any changes or potential problems.

As with most procedures, the NFPA does allow exceptions to the rule of inspections.

From the 2016 Edition of NFPA 25* Sprinklers installed in concealed spaces such as above suspended ceilings shall not require inspection. Sprinklers installed in areas that are inaccessible for safety considerations due to process operations shall be inspected during each scheduled shutdown.

It’s important to keep a record of all inspections. Doing so creates a record of any issues that arise and actions taken, and helps maintain the overall health of the system.

Service providers may or may not use forms to conduct annual inspections that are considered acceptable to all Authorities Having Jurisdiction (AHJ). It’s up to a building owner, facilities manager, etc. to verify that the forms are acceptable. Ideally, the form is acceptable to any who might need to review it and confirm that inspections meet NFPA 25 criteria.

It’s important to note that NFPA 25 doesn’t have a specific form that must be filled out, but it does provide many example forms that are available for use.

Adequate records are not only necessary for inspections, but lend themselves to sprinkler testing, as well.

When do I perform fire sprinkler testing?

It’s best to perform sprinkler testing on a routine basis, according to the age and type of sprinklers within the system.

Although fire sprinkler heads tend to have a long lifespan within a system, the testing frequency increases over time and as they age. The age of the sprinklers, as we discussed above, is based on their installation date. If the date of installation is unidentifiable, the manufacture date of the fire sprinkler heads may be used instead (though their manufacture date may predate the system).

From the 2016 Edition of NFPA 25

A. Sprinklers should first be given a visual inspection in accordance with to determine if a replacement is required. Sprinklers that have passed the visual inspection should then be laboratory tested for sensitivity and functionality. The waterway should clear when sensitivity/functionality tested at 5 psi (0.4 bar) or the minimum listed operating pressure for dry sprinklers.

Until the 50-year mark, it’s not necessary to test standard response sprinkler heads. Because quick-response sprinklers have only been around since about 1980, their lifespan and failure rates are still somewhat unknown. Testing them at 20 years, rather than 50, provides a way to identify issues earlier.

Adapted from Table about testing in the 2016 Edition of NFPA 25

Type Frequency Reference
Standard Response Sprinklers At 50 years and every 10 years thereafter,,
Sprinklers At 75 years and every 5 years thereafter
Dry Sprinklers 10 years and every 10 years thereafter
Sprinklers (extra high or greater temperature solder type) 5 years
Fast Response Sprinklers At 20 years and every 10 years thereafter
Sprinklers in harsh environments as defined by A. 5 years

As is visible in the table, special types of fire sprinklers and those subjected to harsh environments have a much shorter span between testing periods. Dry sprinklers, specifically, have a 50 percent failure rate after they reach the 10-year mark, according to NFPA.

Testing is not necessary for the full set of sprinkler heads within the system, but rather a representative sample.

From the 2016 Edition of NFPA 25* Where required by this section, sample sprinklers shall be submitted to a recognized testing laboratory acceptable to the authority having jurisdiction* A representative sample of sprinklers for testing per shall consist of a minimum of not less than four sprinklers or 1 percent of the number of sprinklers per individual sprinkler sample, whichever is greater.

A representative sample means that sprinklers should not be selected solely on their ease of access. It’s best to select a random sample from different floors, rooms, and areas within the facility. When selecting a sample set, make sure to pick sprinklers from different types and environments.

The sample set must undergo a plunge test. Using the controlled plunge test apparatus, the sprinkler is pressurized with 5 psi (0.4 bar) of air pressure. The test measures the amount of time it takes the fusible element to activate. When a fire sprinkler head from a sample set fails to activate in the appropriate amount of time during the plunge test, it’s necessary to replace all sprinklers within the system.

When do I resort to replacing fire sprinkler heads?

In short, fire sprinkler heads must be replaced if they fail the plunge test, if they are heavily loaded with dust or other contaminants, if they have been painted, or if they are leaking or damaged. And all fire sprinklers manufactured before 1920, according to NFPA 25, must be replaced.

An inspection can provide a good indication as to whether any of the sprinklers within the system need to be replaced.

From the 2016 Edition of NFPA 25* Any sprinklers that show signs of any of the following shall be replaced:

(1) Leakage
(2) Corrosion detrimental to sprinkler performance
(3) Physical damage
(4) Loss of fluid in the glass bulb heat-responsive element
(5) Loading detrimental to sprinkler performance
(6) Paint other than that applied by the sprinkler manufacturer

Because sprinklers fail more as they age, replacement might seem like a better option rather than continuing to test them periodically. It’s helpful to weigh the costs of testing in comparison to purchasing new fire sprinkler heads to determine the best plan of action.

Sprinklers considered “heavily loaded” are those that have dust, dirt, debris, or grease that is difficult to remove without touching the sprinkler head. Before you resort to replacement, you can try a touch-free method of cleaning dirty fire sprinkler heads. If you find it necessary to wipe or scrub with a cleaning solution, then it’s necessary to replace the loaded sprinkler heads.

A dust-covered, or loaded, fire sprinkler head.

A dirty or "loaded" fire sprinkler head.

Never, under any circumstances, paint fire sprinklers (or cover plates). If a fire sprinkler head has been painted, it needs to be replaced by a sprinkler with the same characteristics, according to NFPA 13 Painting sprinkler heads can cause irreparable damage that can cause the sprinklers to malfunction.

It goes without saying that leaking or damage can hinder the proper operation of a fire sprinkler head. Leaking or damaged heads must be replaced as soon as possible, which is why it’s helpful to have a fire sprinkler head replacement cabinet on site.

A corrosion-damaged fire sprinkler head.

A fire sprinkler head badly damaged by corrosion. Source: Garden Grove Water Damage.

If you’re in the market to replace fire sprinkler heads, consider purchasing from QRFS! We offer various commercial and residential fire sprinklers from Viking, Victaulic, Tyco, Reliable, and Senju. Regardless of whether your job needs one sprinkler head or hundreds, we’ve got them in-stock and ready to ship to you!

When you purchase from us, you benefit from our quality customer service and extensive product knowledge. We try to stay up-to-date on NFPA Code and industry best practices so that we can provide you with the right information at the right time.

Click here to browse our selection of commercial fire sprinkler heads.

More questions? Reach out to us by calling +1 (888) 361-6662 or emailing [email protected].


This blog was originally posted by Jason Hugo and Anna Hartenbach at on August 24, 2017, and updated on January 1, 2019. If you found this article helpful, check us out at or on Twitter @QuickResponseFS.