Drain System Installation & Troubleshooting

These economical water removal systems from Little Giant are an inexpensive, simple way to remove grey water (not sewage) from laundry trays and sinks that are below your main sewer/septic lines.

Little Giant Pump Installation and Troubleshooting

Little Giant Pump Diagram


1. Clean any debris from sump pit and set pump in center of pit. A solid bottom will prevent clogging of the pump from sand and dirt.

2. Connect discharge piping and run it to the nearest sewer or surface outlet. Use pipe joint compound at all connections. Sump pumps can be piped to discharge into the house drainage system, to a dry well, splash block or to a storm drain, depending on local plumbing codes. The discharge pipe should be as short as possible and contain as few elbows as possible. The discharge pipe should be the same diameter as the discharge size to reduce pipe friction losses. Smaller pipe will restrict capacity and reduce pump performance. The sump pump comes with 1-1/2" female pipe thread discharge, and 1-1/4" FNPT reducing bushing.

3. Always install a union in the discharge line, just above the sump pit, to allow for easy removal of the pump for cleaning or repair.

4. In situations where the piping is long, the vertical discharge is above 7 or 8 feet, or a small pit has been provided, use of a check valve is recommended to prevent backflow of water into the sump. When a check valve is used, drill a relief hole (1/8" or 3/16" diameter) in the discharge pipe. This hole should be located below the floor line between the pump discharge and the check valve. Unless such a relief hole is provided, the pump could "air lock" and will not pump water even though it will run.

5. Tape pump and switch cords to discharge line with electrician's tape. This will protect the cords from damage and will prevent power cords from interfering with the float.

6. TEST THE PUMP AFTER ALL CONNECTIONS HAVE BEEN MADE. Run water into sump. Do not attempt to operate the pump without water; this will damage the seals and bearings and could result in permanent damage to the pump. Fill sump to normal "on" level and allow pump to remove water to the normal "off" level (see fig. 2).

7. Place cover over sump. This cover will prevent solid debris from filling the pit. prevent odors, and guard against accidental injury.

Trouble Shooting Information

Problem Probable Causes Corrective Action
Pump will not shut off

Note: Before trouble shooting automatic control, check to see that the pump operates on manual control. To do this, create slight vacuum on breather tube (near plug), then close off tube with thumb, plug into wall outlet. If the pump works, proceed to check switch; if not, fault is in the pump or power supply.

Diaphragm switch Replace switch
Weak or hardened rubber diaphragm Replace rubber diaphragm
Plugged vent tube Clear vent tube of any obstructions
Dirt or sediment lodged between retainer ring and rubber diaphragm causing contacts to remain closed Clean area around rubber diaphragm
Pump is air locked Shut power off for approximately 1 minute, then restart. Repeat several times to clear air from pump. If system includes a check valve, a 3/16" hole should be drilled in discharge pipe approximately 2" above discharge connections.
Liquid inflow matches pump capacity Larger pump required
Defective switch Disconnect switch, check 2/ohmmeter, Open-infinite resistance, closed-zero
Loose connection in level control wiring Check control wiring
Pump runs but does not discharge liquid Check valve installed backwards Check flow indicating arrow on check valve body to insure it is installed properly.
Check valve stuck or plugged Remove check valve and inspect for proper operation
Lift too high for pump Check rating table
Inlet to impeller plugged Pull pump and clean
Pump is air locked (See corrective action above)
Pump does not deliver rated capacity Lift too high for pump Check rated pump performance
Low voltage, speed too slow Check for proper supply voltage to make certain it corresponds to nameplate voltage
Impeller or discharge pipe is clogged Pull pump and clean. Check pipe for scale corrosion
Impeller wear due to abrasives Replace worn impeller
Pump cycles continually No check valve in long discharge pipe allowing liquid to drain back into sump Install a check valve in discharge line
Check valve leaking Inspect check valve for correct operation
Sump pit too small for inflow Install larger sump pit

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