16
Troubleshooting Checklist
Problem
Possible Causes
Pump does
not run or
hums
• Line circuit breaker is off, or fuse is blown or loose.
• Water level in the sump has not reached turn-on level as
indicated in the installation drawing.
• Pump cord is not making contact in the receptacle.
• Float is stuck. It should operate freely in the basin.
• Debris may be stuck in the impeller.
• If all of the above are OK, then the motor winding may be open
or the capacitor may be defective.
Pump runs but
does not
deliver water
• Check valve is installed backwards. Arrow on the valve should
point in the direction of flow.
• Discharge shut-off valve (if used) may be closed.
• Pump is air-locked. Start and stop several times by plugging and
unplugging cord. Check for clogged vent hole in pump case.
• Impeller or volute openings are fully or partially clogged.
Remove pump and clean.
• Inlet holes in pump base are clogged. Remove pump and clean
the openings.
• Vertical pumping distance is too high. Reduce distance or resize
pump.
Pump runs
and pumps out
sump, but
does not stop
• Float is stuck in the up position. Be sure the float operates freely
in the basin.
• Defective float switch.
Pump runs but
delivers only a
small amount
of water
• Pump is air-locked. Start and stop several times by plugging and
unplugging the cord.
• Check for a clogged vent hole in the pump case.
• Vertical pumping distance is too high. Reduce the distance or
resize the pump.
• Inlet holes in pump base are clogged. Remove pump and clean
the openings.
• Impeller or volute openings are fully or partially clogged.
Remove the pump and clean.
Fuse blows or
circuit breaker
trips when
pump starts
• Pump impeller is partially clogged, causing motor to run slow
and overload. Remove pump and clean.
• Motor stator may be defective.
• Fuse size or circuit breaker may be too small. Must be 15 amps.
• Impeller or volute openings are fully or partially clogged.
Remove pump and clean.
• Water lead inside the pump motor.
