Pump runs or hums
but does not pump
Water is present
inside motor housing
Pump does not turn
off
Poor grinding
performance
Low pumping
performance
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Discharge is blocked
or restricted
Check valve is stuck
closed or installed
incorrectly
Pump is air-locked
Pump impeller/cutter is
jammed
Max. lift height (Head)
has been exceeded
(see Fig. E)
Pump seals have been
compromised
Defective float or build-
up on surroundings is
restricting free
movement of the float.
Control panel failure
Low Voltage
THREE PHASE
PUMPS ONLY:
Pump is rotating in
reverse.
Large Grinder Cutter
Gap
Impeller wear
Pump is rotating in
reverse.
Check the discharge line for blockage or
for ice if the line passes through or into
cold areas.
If check valve is present, remove and
inspect for freedom of operation and
proper installation.
Remove the pump and inspect the anti-
airlock hole. Remove any debris or rust
that may be blocking the hole. Verify
that the pump turn off level has not
changed from its factory specified
setting.
With the pump de-energized, inspect
bottom of pump for foreign material
blocking the impeller or cutter. If no
blockage is found, try rotating the cutter
using a hex key and the cutter bolt. If
the cutter will not rotate, consult Liberty
Pumps for further instruction.
Attempt to re-route piping to a lower
elevation. If this is not possible, a larger
pump may need to be installed.
Consult Liberty Pumps.
Check that the float is free to move. If
build-up restricts float, clean and
reinstall. Otherwise, consult Liberty
Pumps.
Have an electrician inspect/evaluate
control panel. Consult control panel
manufacturer for further assistance.
Have electrician check wiring for proper
capacity and measure voltage while
pump is in operation.
Place pump on ground and inspect
rotation while pump is operating. If
rotation is reversed, have an electrician
interchange two of the power leads in
the control panel.
Consult Liberty Pumps for further
troubleshooting and assistance.
Consult Liberty Pumps for additional
troubleshooting and replacement parts.
THREE PHASE PUMPS: Place pump
on ground and inspect rotation while
pump is operating. If rotation is
reversed, have an electrician
interchange two of the power leads in
the control panel.
SINGLE PHASE PUMPS: Contact
Liberty Pumps immediately. Do not
switch power leads or continue to
operate the pump.
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