Water Pump: Shurflo 5.7 Pump Troubleshooting

Reducing unnecessary restrictions to the inlet and the outlet tubing will allow the pump to run freely, maximizing the Smart Sensor’s performance, quietness and eliminate the possibility of cavitation (starving the pump).

Pump cycling may be caused by excessive back pressure created by one or more of the following within a plumbing system:

  • Low flow from a partially open faucet.
  • Water filters not on separate feed lines.
  • Clogged water filters.
  • Restrictive elbows shut-off and check valves
  • Use as few elbows and valves as possible in the first two feet [.6M] after the pump.
  • Flow restrictors in faucets and showerheads.
  • Long lengths of small I.D. lines.
  • Pipe/tubing should be at least 1/2” [13mm] I.D. from main lines.
  • Restrictive fittings and connections (elbows, “T’s”, feeder lines to the faucet, etc.)

If the pump is cycling rapidly increase the setting by turning the screw clockwise (1/2 to 3/4 turn MAX.) If the pump continues to cycle after making the pressure adjustments contact SHURflo customer service.

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PUMP WILL NOT START/BLOWS CIRCUIT

  • Electrical connections, fuse, breaker, main switch, and ground connection.
  • Is the motor hot? Thermal protector may have triggered; it will reset when cool.
  • Is voltage present at the pump?
  • Charging System for correct voltage (9-14) and good ground.
  • For an open or grounded circuit or motor; improperly sized wire.
  • For seized or locked diaphragm assembly (water is frozen?)
  • Is wire size too small? Minimum 14 AWG wire required.

WILL NOT PRIME/SPUTTERS: (No discharge / Motor runs)

  • Is the strainer clogged with debris?
  • Inlet cavitation from restrictions, small tubing? Outlet restrictions?
  • Is there water in the tank, or air in the hot water heater?
  • Is the inlet plumbing sucking air in the air at connections (vacuum leak)?
  • Is the inlet/outlet plumbing severely restricted or kinked?
  • Proper voltage with the pump operating (9 – 14 volts).
  • For debris in pump inlet/outlet valves or swollen/dry valves.
  • Pump housing and drive assembly for cracks or loose screws.

PUMP WILL NOT SHUT OFF/RUNS WHEN FAUCET IS CLOSED

  • Output side plumbing for leaks, and inspect for leaky valves or toilet.
  • For air trapped in the outlet side (water heater) or pump head.
  • For bad transducer or transducer wire connections.
  • For loose drive assembly or pump head screws.
  • Are the valves held open by debris or swollen?

LEAKS FROM PUMP HEAD OR COVER

  • For switch diaph. leaking undercover.
  • For puncture diaphragm, if the water is present in the drive.
  • Leaks from fitting? Check o-ring in the groove? O-ring lubricated properly

NOISY OR ROUGH OPERATION

  • For plumbing which may have vibrated loose.
  • Is the pump plumbed with rigid pipe causing noise to transmit?
  • Does the mounting surface amplify noise?
  • For mounting feet that are loose or compressed too tight.
  • For loose pump head to motor screws.
  • For air in the system.
  • The motor with pump head removed. Is the noise from motor when it runs alone?