Backflow Preventer Discharging Water: What Facility Staff Should Do
Water coming from a reduced-pressure backflow assembly needs investigation. A discharge opening performs a protective function; closing that opening is not a repair.
Last reviewed 2026-09-15 · General facility-maintenance information, not a substitute for site procedures, manufacturer instructions, codes, or qualified professional judgment.
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What to check first
Bring these
- Flashlight
- Wet-floor signs and barrier kit
- Water leak alarm
Step-by-step procedure
- 1Protect accessKeep occupants away from discharge and electrical hazards. If water is spreading, contact the building lead immediately and call the plumbing/backflow service provider.
- 2Identify the assemblyFrom normal access, record its make, model, size, service label and visible test tag. Confirm whether it serves domestic water, irrigation or fire protection before anyone considers isolation.
- 3Describe the dischargeRecord whether it is a drip or sustained flow, when it began and whether a supply interruption occurred. Do not cycle valves to reproduce the event.
- 4Check surrounding conditions visuallyReport a blocked receiving drain or damaged air-gap fitting without obstructing the assembly outlet. The Watts 909 reference below applies to that series, not every installed assembly.
- 5Arrange qualified testingA trained backflow technician should diagnose and test the assembly using the correct instructions. Document repair and any required retest before treating the event as closed.
Leave a useful maintenance record
Record the exact location, observed condition, time, actions taken, person contacted and follow-up owner. Keep unresolved items visible. A completed checklist means the check was performed; it does not automatically mean the equipment passed or is safe.
References and further reading
Watts: Series 909 / LF909 installation and maintenance instructions — https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/23409-source/638748128830000000/0834246-rp-is-909s-pdf.pdf Use the installed equipment manual and your site plan for equipment-specific procedures.
Stop and call a licensed professional when
- Continuous flow, possible contamination, an unidentified service or any fire-protection impairment requires urgent coordination with the responsible specialists.
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