10 Most Common NFPA 25 Sprinkler Inspection Findings
Inspectors and property managers see the same NFPA 25 findings over and over. If you own or manage a commercial building with a sprinkler system, knowing these in advance means fewer surprises, faster correction, and a smoother path to a clean report. These are the ten items most frequently cited on NFPA 25 inspection reports across the United States.
- 1
Painted or Obstructed Sprinkler Heads
Sprinkler heads painted over during a tenant improvement, or blocked by stored goods within the 18-inch clearance, are the single most common finding. NFPA 25 §5.2.1.1.1 requires inspection of every head. If any part of the head is painted, loaded with corrosion/dust, or blocked, it must be replaced or cleared.
📖 NFPA 25 §5.2.1.1.1 - 2
Pressure Gauges Past 5-Year Replacement
All pressure gauges on a sprinkler system must be replaced or recalibrated every 5 years. Gauges with illegible faces or stuck needles fail inspection. The sticker on each gauge must show a date within 5 years.
📖 NFPA 25 §5.2.4.3 - 3
Missing or Illegible Hydraulic Nameplate
The hydraulic design nameplate must be permanently affixed to the system riser. If it is missing, corroded, or painted over, the inspection fails. Replacement requires engineered calculations.
📖 NFPA 25 §5.2.6 - 4
Blocked Fire Department Connection (FDC)
Fire Department Connections must be unobstructed, clearly identified, and have intact caps. Overgrown landscaping, parked vehicles, and missing caps are common findings. Caps with internal threads damaged also cited.
📖 NFPA 25 §13.7.1 - 5
Main Drain Test Pressure Drop Exceeding 10%
The annual main drain test must show residual pressure within 10% of the prior year's reading. A larger drop indicates water supply degradation and requires investigation — often a nearly closed valve or water main issue.
📖 NFPA 25 §13.2.5 - 6
Control Valves Not Properly Sealed or Chained Open
All sprinkler control valves must be in the open position AND secured with a lock, seal, or electronic supervision. Missing seal or unsecured valves is a major finding — a closed valve is the #1 cause of system failure during an actual fire.
📖 NFPA 25 §13.3.2 - 7
Antifreeze System Concentration Out of Spec
Antifreeze loops must be tested annually for proper concentration. Many legacy antifreeze systems use glycerin or propylene glycol that has been diluted over time. Concentration outside the listed range is an immediate correction.
📖 NFPA 25 §5.3.3 - 8
Missing 5-Year Internal Pipe Inspection
Every sprinkler system requires a 5-year internal pipe inspection. Many owners are unaware and fail this item automatically on inspection #6. Dry-pipe systems in particular can show significant corrosion that only shows up during internal inspection.
📖 NFPA 25 §14.2 - 9
Fire Pump Weekly / Monthly Test Records Missing
If the facility has a fire pump, the weekly (diesel) or monthly (electric) churn test records must be available on-site. Missing logs are cited even if the pump is in perfect condition. 2020 NFPA 25 changed electric pumps to monthly — verify your jurisdiction has adopted.
📖 NFPA 25 §8.3 - 10
Dry Valve Trip Test Overdue or Trip Time Excessive
Dry-pipe valves require an annual partial trip test and full-flow trip test every 3 years. Trip times exceeding 60 seconds for schedule-system or exceeding design time for a hydraulically calculated system are findings. Often indicates air compressor issues or valve degradation.
📖 NFPA 25 §13.4.3
In Summary
None of these are catastrophic on their own — but together they represent the baseline a well-run commercial facility keeps ahead of. Pre-inspecting against this list monthly, not just annually, is the lowest-cost way to maintain a clean NFPA 25 record.
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