Problem
Pump will not turn on or shut
off.
Pump runs or hums but does
not pump.
Pump short-cycles.
Pump runs periodically when
fixtures are not in use.
Water or soap suds come out
of vent pipe.
Pump operates noisily.
*NOTE: Liberty Pumps, Inc. assumes no responsibility for damage or injury due to disassembly beyond float removal in the field.
Disassembly, other than at Liberty Pumps or its authorized service centers, automatically voids warranty.
7212000F
Table 1. Troubleshooting Matrix
Possible Cause
Tripped circuit breaker, tripped GFCI, blown
fuse, or other interruption of power.
Improper voltage.
Plugged vent, or quick-vent in use.
Defective float switch or build-up on tank wall
restricting free movement of float switch.
Discharge is blocked or restricted.
Check valve is stuck closed or installed wrong.
Total head (lift height) has been reached (refer
to Figure 8)
Pump impeller is jammed.
Trap or inlet piping is clogged.
Plugged vent, or quick-vent in use.
Defective float switch.
Check valve was not installed, is stuck open, or
is leaking.
Check valve was not installed, is stuck open, or
is leaking.
Faucets are dripping.
Vent pipe is too short or too small in diameter.
Defective float switch.
Rate of inflow exceeds pump output.
Foreign objects in impeller cavity.
Piping to house structure is too rigid.
Copyright © Liberty Pumps, Inc. 2018 All rights reserved.
Correction
Reset tripped circuit breaker, reset GFCI, replace
blown fuse with properly sized fuse, check that the
unit is securely plugged in, investigate power
interruption.
Have an electrician check all wiring for proper
connections and adequate capacity.
Verify that an unrestricted vent at least 1-¼" in
diameter is in use. Quick-vents shall not be used.
*Remove access cover and check that float is free to
move. If build-up restricts float, clean and reinstall. If
defective, replace switch.
Check the discharge line for blockage, including ice
if the line passes through or into cold areas.
Remove and examine for freedom of operation and
proper installation.
Try routing pipe to a lower level. If not possible,
another pumping station may be required at a level
of roughly half the total head (lift).
*Disassemble unit to expose pump impeller.
Remove foreign material. Reassemble.
Check the trap and inlet piping for restrictions.
Verify that an unrestricted vent at least 1-¼" in
diameter is in use. Quick-vents shall not be used.
*Remove access cover and check that float is free to
move. If build-up restricts float, clean and reinstall. If
defective, replace switch.
Remove and examine for freedom of operation and
proper installation.
Remove and examine for freedom of operation and
proper installation.
Repair faucets to eliminate dripping.
Verify that an unrestricted vent at least 1-¼" in
diameter is in use.
*Remove tank cover and check that float is free to
move. If build-up restricts float, clean and reinstall. If
defective, replace switch.
Use valve on the inlet to reduce rate of inflow.
*Disassemble unit to expose pump impeller.
Remove foreign material. Reassemble.
Replace a portion of the discharge pipe with rubber
hose to absorb noise.
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