10 | EN
Copyright © Liberty Pumps, Inc. 2020 All rights reserved.
2399000D
Pump operates with
control panel selector
switch in Hand position
but does not operate in
Auto position.
Control circuits malfunctioning.
Check float level control or the alternator relay for issues.
Check control panel.
Pump runs, but does
not turn off.
Control panel selector switch in Hand position.
Set selector switch to Auto position.
Float switch unable to move to the Pump OFF
position due to interference with the side of
basin or other obstruction.
Position the pump or float switch so that it has adequate
clearance for free movement.
Control panel failure.
Check control panel.
Defective float switch.
Replace float switch.
Pump runs or hums, but
does not pump.
Discharge is blocked or restricted.
Check the discharge line for foreign material, including
ice if the discharge line passes through or into cold areas.
Check valve is stuck closed or installed backward. Remove check valve(s) and examine for freedom of
operation and proper installation.
Gate or ball valve is closed.
Open gate or ball valve.
Total head (lift height) is beyond pump's
capability.
Route piping to a lower level. If not possible, a larger
pump may be required. Consult Liberty Pumps.
Obstructed impeller or volute.
Remove obstruction.
Pump does not deliver
proper capacity.
Discharge valve(s) 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.
Total head (lift height) is beyond pump's
capability.
Route discharge piping to a lower level. If not possible, a
larger pump may be required. Consult Liberty Pumps.
Low liquid level.
Check liquid level.
Incorrect motor rotation.
Contact factory.
Obstruction in pump or piping.
Remove obstruction.
Motor stops and then
restarts after short
period but overload
heaters in starter do not
trip.
Pump operating on a short cycle due to basin
being too small.
A larger basin may be required. Consult Liberty Pumps.
Water returning to basin due to leaking check
valve.
Replace check valve.
Pump cycles too
frequently.
Improper float switch setting.
Adjust float switch setting.
Check valve not installed, stuck open, or leaking. Install check valve(s); remove check valve and examine
for freedom of operation and proper installation.
Pump runs periodically
when fixtures are not in
use.
Check valve not installed, stuck open, or leaking. Install check valve(s); remove check valve and examine
for freedom of operation and proper installation.
Fixtures are leaking.
Repair fixtures as required to eliminate leakage.
Table 2. Troubleshooting Matrix (continued)
Problem
Possible Cause
Corrective Action
