If your building has a fire pump, it exists for a reason: the public water supply alone can’t deliver the pressure your sprinkler or standpipe system needs. That’s common in taller buildings, large warehouses and facilities with high water demand.
A fire pump that won’t start — or can’t deliver its rated performance — can leave parts of a building without adequate sprinkler protection. That’s why pumps are tested on a regular schedule under NFPA 25.
Two kinds of tests
1. The no-flow (churn) test
A churn test runs the pump without flowing water out of the system. It confirms the pump starts automatically, runs smoothly and maintains proper pressure and temperature.
Under NFPA 25, no-flow tests are performed weekly or monthly, depending on the pump driver and the building’s conditions. Diesel-driven pumps are generally tested weekly; many electric-motor pumps may be tested monthly where the standard’s conditions are met. Run times are set by the standard and differ for diesel and electric drivers.
During a churn test, readings such as suction and discharge pressure, pump speed and (for diesel) engine temperature and oil pressure are recorded. Packing glands, bearings and the pump room are checked for leaks, overheating and unusual noise.
2. The annual flow test
Once a year the pump is tested while flowing water — typically through a test header or flow meter — at several points: no flow (churn), 100% of rated flow and 150% of rated flow. The measured pressures and flows are plotted and compared against:
- The manufacturer’s certified pump curve
- The original acceptance test
- Previous annual tests
A pump whose performance has dropped meaningfully below those benchmarks needs investigation.
What the results tell you
Flow test data is a health report for your pump. Gradual decline can point to impeller wear, suction issues, obstructions or driver problems. Catching a trend early allows repairs to be planned rather than discovered during an emergency.
Other components that get inspected
- Controller — the panel that starts and monitors the pump
- Transfer switch — where an alternate power source is provided
- Jockey pump — the small pump that maintains system pressure
- Diesel engine and fuel supply — on diesel units
- Pump room — temperature, ventilation, lighting and housekeeping
Planning for test day
Annual flow tests discharge a large volume of water. Your provider should plan a safe discharge path, notify the alarm monitoring company and coordinate with building staff.
Key takeaways
- Fire pumps get frequent no-flow tests (weekly or monthly) and an annual flow test.
- Annual results are compared against the pump curve and previous tests.
- Trends in test data reveal problems before failure.
- Coordinate pump testing with sprinkler and alarm service.
Learn about our fire pump testing services.
Sources & references
- NFPA 25 — Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems
- NFPA 20 — Installation of Stationary Pumps for Fire Protection
YearRound Editorial Team · Fire & Life Safety Education
Articles from the YearRound Fire & Life Safety team are written to help commercial property owners, facility managers and business operators understand their fire protection systems. Technical articles are reviewed for accuracy against current published standards before publication. Requirements vary by jurisdiction — always confirm with your local Authority Having Jurisdiction.