5595000B
Copyright © Liberty Pumps, Inc. 2022 All rights reserved.
9 | EN
Table 2. Troubleshooting Matrix
Problem
Possible Cause
Corrective Action
Pump does not start.
Control panel selector switch in Off position.
Set selector switch to Hand or Auto position.
Blown control circuit transformer fuse.
Replace fuse.
Tripped circuit breaker, blown fuse, or other
interruption of power.
Reset tripped circuit breaker; replace blown fuse
with properly sized fuse; investigate power
interruption.
Improper voltage.
Have an electrician check all wiring for proper
connections and adequate voltage and capacity.
Float switch is unable to move to the PUMP ON
position due to interference in basin or other
obstruction.
Position the pump or float switch so that it has
adequate clearance for free movement.
Insufficient liquid level.
Verify the liquid level is allowed to rise enough
to activate float switch(es).
Defective float switch.
Replace float switch.
Obstructed impeller or volute.
Remove obstruction.
Loose wiring connections.
Check and tighten all connections.
Thermal overload tripped.
Wait for pump to cool to operating
temperature.
Pump does not deliver proper
capacity.
Discharge gate valve partially closed or clogged.
Check the discharge line for foreign material,
including ice if the discharge line passes
through or into cold areas.
Check valve partially clogged.
Raise liquid level up and down to clear; remove
check valve to remove obstruction.
Incorrect motor rotation.
1-phase: verify capacitor wiring in Figure
1, else
consult factory.
3-phase: correct pump rotation direction. Refer
to section
Low liquid level.
Check liquid level.
Obstruction in pump or piping.
Remove obstruction.
Total head is beyond pump's capability.
Route discharge piping to a lower level. If not
possible, a larger pump may be required.
Consult Liberty Pumps.
Pump runs but does not turn off.
Pump is airlocked.
Turn pump off and let set for several minutes,
then restart.
Float switch unable to move to the PUMP OFF
position due to interference with the side of
basin or other obstacle.
Position the pump or float switch so that it has
adequate clearance for free movement.
Control panel selector switch in Hand position.
Set selector switch to Auto position.
Control panel failure.
Check control panel.
Defective float switch.
Replace float switch.
Missing or faulty curb stop/swing check valve
allowing system pressure to feed back through
discharge piping.
Verify presence of a curb stop check valve or
replace curb stop/swing check valve assembly.
