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    fire-fabrication troubleshooting

    Fire pump won't start or maintain pressure

    Common symptoms: fire pump won't start; jockey pump runs constantly; fire pump low pressure; fire pump fault; pump not maintaining pressure

    Stop and call a pro if:

    • this is a LIFE-SAFETY system — never leave a fire pump impaired or out of AUTO without authorization
    • do not work inside the fire-pump controller or on electric/diesel driver components; high voltage and stored energy hazards
    • impairment requires an impairment program, notifying the AHJ and monitoring company, and often a fire watch

    Step-by-step diagnostic flow

    1. Step 1

      Is there an active fire, or any smoke, sparking, fuel leak (diesel), or burning smell at the pump or controller?

      Any active emergency at the fire pump takes priority over troubleshooting.

    2. Step 2

      Is the fire-pump controller selector in AUTO (not OFF, HAND, or a tripped/alarm state)?

      A fire pump must sit in AUTO so it starts automatically on a pressure drop. You may read the selector position; do not open the controller.

    3. Step 3

      Is the jockey (pressure-maintenance) pump running constantly or short-cycling to hold system pressure?

      The jockey pump makes up small losses. If it runs constantly, the system is losing pressure — usually a leak or an open drain/test valve — not normal.

    4. Step 4

      Are the suction-supply and discharge valves fully open and is suction pressure within normal range on the gauge?

      A throttled/closed supply valve or low suction pressure starves the pump. Only confirm valve position and read gauges — do not reposition supply valves without authorization.

    5. Step 5

      Is this an electric or diesel fire pump, and what does the controller alarm indicate?

      Electric controllers flag phase/power/overload faults; diesel controllers flag fuel, battery, overspeed, or temperature faults. Note the alarm; do not service the driver.

    Possible outcomes

    Active emergency — evacuate / call 911

    high confidence

    Fire, smoke, sparking, or a fuel leak at the pump is an emergency that overrides troubleshooting.

    Safe next steps
    • Evacuate and call 911
    • Keep clear of the controller and driver
    • Notify the monitoring company once safe
    Active fire or equipment hazard

    Controller wasn't in AUTO — restored

    high confidence

    A fire pump left out of AUTO won't start automatically; returning it to AUTO restores normal automatic operation.

    Safe next steps
    • Confirm the controller shows normal/AUTO with no alarms
    • Find out why it was taken out of AUTO (recent testing?) and confirm any impairment was closed out
    • Notify the monitoring company that it's back in service
    What to document for a pro
    • Whether recent testing left it out of AUTO
    • Controller make/model
    A pump out of AUTO is an impairment that must be closed properly

    Jockey pump cycling indicates a system leak — call a contractor

    high confidence

    A constantly running or short-cycling jockey pump means the system is losing pressure, typically from a leak or an open test/drain valve — a licensed contractor must locate and correct it.

    Safe next steps
    • Do not close supply valves or take the system out of service yourself
    • Check for an obviously open inspector's test/drain valve and report it
    • Notify the monitoring company and call a licensed fire-protection contractor
    What to document for a pro
    • Jockey pump cycle frequency
    • System pressure trend and gauge readings
    • Any audible/visible leaks or open test valves
    Locating/repairing a leak on a fire system is licensed work

    Supply/suction problem — fire-protection contractor

    medium confidence

    A closed/throttled supply valve or low suction pressure starves the pump; correcting valve position or supply issues on a life-safety system must be authorized and verified.

    Safe next steps
    • Do not reposition supply valves without authorization — report the finding
    • Notify the monitoring company / building authority
    • Engage a licensed fire-protection contractor to restore and verify supply
    What to document for a pro
    • Suction and discharge gauge readings
    • Which valve is closed/throttled
    • Pump and controller make/model
    Supply-valve and suction work is authorized, licensed work

    No obvious cause — emergency fire-protection contractor

    low confidence

    If the pump is in AUTO, the jockey is normal, and supply is good but it still won't maintain pressure, the fault is in the pump, driver, or controller and requires professional diagnosis — the pump cannot be left impaired.

    Safe next steps
    • Do not open the controller or service the pump
    • Notify the monitoring company and AHJ that the pump may be impaired; ask about a fire watch
    • Call an emergency fire-protection contractor
    What to document for a pro
    • Controller make/model and any alarm text
    • Suction/discharge/system gauge readings
    • Whether the pump attempts to start at all
    A fire pump may not be left impaired; needs immediate licensed service

    Driver/controller alarm — emergency fire-protection contractor

    high confidence

    Electric power/phase/overload or diesel fuel/battery/temperature/overspeed alarms indicate a driver or controller fault that leaves fire protection impaired and must be serviced immediately by a licensed contractor.

    Safe next steps
    • Do not work inside the controller or on the driver
    • Record the exact alarm; leave the controller as found (do not reset)
    • Notify the monitoring company and AHJ, arrange a fire watch if directed, and call an emergency fire-protection contractor
    What to document for a pro
    • Electric vs diesel driver
    • Exact controller alarm text
    • Controller and pump make/model
    • Fuel/battery status for diesel units
    Driver/controller faults on an impaired fire pump are emergency licensed work
    Diagnostic guidance only. If unsure, stop and call a licensed professional — gas, electrical, and refrigerant work is hazardous to untrained users.

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