24/7 EmergencySandton · Midrand
    Taps & Fittings

    Why does my tap sputter or spit water?

    A tap that sputters and spits has air in the line. It is normal after municipal works, after the supply has been shut off and restored, or after a pressure pump has run dry and lost its prime. Running every tap for a couple of minutes, cold then hot, clears most cases. Sputtering that persists after that points at a geyser air vent or a pump drawing air.

    RoutineDiagnostic R650

    Quick answer

    A tap that sputters and spits has air in the line. It is normal after municipal works, after the supply has been shut off and restored, or after a pressure pump has run dry and lost its prime. Running every tap for a couple of minutes, cold then hot, clears most cases. Sputtering that persists after that points at a geyser air vent or a pump drawing air.

    Common causes

    • Air introduced after municipal supply work or a mains interruption
    • Pressure pump losing prime and drawing air from an empty tank
    • Failing geyser air vent or vacuum breaker letting air into the hot line
    • Partly closed valve creating turbulence at the fitting
    • Tank level low enough that the outlet is occasionally uncovered
    • Leak on the suction side of a pump drawing air in

    What you can do now

    1. 1Run every tap, cold then hot, for two minutes each starting with the one lowest in the house
    2. 2Check the backup tank level if you have one
    3. 3Note whether it affects hot only, cold only, or both — hot only points at the geyser vent
    4. 4Check whether the pump is cycling oddly, which suggests it is drawing air
    5. 5Repeat the flush once more after an hour before concluding it has not worked

    When to call a professional

    If sputtering persists after thoroughly flushing the system, have the geyser air vent and the pump suction side checked. Air being drawn in continuously means there is a path for it, and on the pump side that same path can let water out. Call sooner if the pump is short-cycling as well, since running a pump on air damages the seals quickly.

    Typical cost in Johannesburg

    Diagnostic R650

    Indicative ranges only. We provide written, itemised quotes before any work.

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