Sump, Effluent & Sewage Pumps Troubleshooting

This “TROUBLESHOOTING” information is intended to guide in the general determination of pump problems and their solutions. Each manufacturer normally provides a description of warranty conditions. Some pump warranties are immediately voided if the unit is disassembled. Be sure to thoroughly read the owner's manual and warranty.

Installation and parts manuals are provided only as reference tools. Neither the manufacturer nor the Seller makes any representation or warranty of any kind to the Buyer that he or she is qualified to neither install nor make any repairs to the product. In fact, the manufacturer and the Seller expressly state that installation, repairs and parts replacements should be undertaken by qualified and competent technicians or contractors and not by the Buyer. The Buyer assumes all risk and liability arising out of his or her installation or repair to the original product.



Pump motor does not run



  • Pump power cord not connected to power receptacle or making poor contact. (Check pump cord cap prongs for tightness and corrosion. Replace plug or clean plug prongs with abrasive paper or have electrical receptacle replaced. Branch circuit not connected or defective circuit breaker. Fuse blown or circuit breaker tripped. Test for power with light bulb. Check fuses & breakers. Replace fuse as required. Note size recommended by pump manufacturer and pump nameplate rating. Use slow-blow type to withstand starting load or reset circuit breaker. Call an electrician to repair the circuit.)
  • Branch circuit wiring too small to carry pump load. (Have line voltage checked and compare with manufacturer's specifications. Have pump connected to separate branch circuit. Call electrician to repair circuit.)
  • Pump motor overload tripped. (Allow pump to cool for 5-10 minutes and reconnect, if overload trips again take corrective action. Have line voltage checked and compare with manufacturer's specifications. Have electrician or power company check branch circuit voltage. Have pump connected to separate branch circuit. Contact Authorized Service Center.
  • Automatic liquid level control switch defective. (Remove pump, disconnect power, connect to rated voltage and actuate control switch. Readjust control floats or weights. Replace liquid level control)
  • Internal motor defect (Remove pump, disconnect power, connect to rated voltage and actuate control switch. Contact Authorized Service Center.)
  • Exceptionally low voltage. (Have line voltage checked and compare with manufacturer's specifications. Have electrician repair the circuit. Call Power Company.)
  • Impeller blocked or bound. (Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Clean volute and impeller and remove any blockage.)
  • Bearings frozen. (Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Free and lubricate lower bearing of column pump. Contact Authorized Service Center to replace pump bearing.)
  • Water temperature too high. (Observe source and amount of water inrush. Measure water temperature. Add cold water to sump and test. Install high temperature pump or reduce temperature of incoming water.)
  • Water level not sufficiently high to actuate control switch. (Add water to sump and observe turn-on. Readjust control floats or weights.)
  • Float operation obstructed or restrained. (Add water to sump and observe turn-on. Readjust control floats or weights.)
  • Float rod bent or obstructed by debris. (Examine and observe. Readjust control floats or weights.)
  • Diaphragm control skirt lost trapped air. (Manually override control to check pump operations, if override is provided by manufacturer. Lift pump above fluid level in sump. Then holding pump straight and vertical, place pump back into sump to retrap air in control skirt.)
  • Moisture in breather tube. (Examine and observe. Remove source of moisture such as dripping pipes, washing machine discharge splash etc. Plug cord into receptacle upside down to prevent moisture from entering breather tube. Return pump to service center for new power cord.)
  • Passage from control skirt to diaphragm obstructed. (Examine and observe. Clean passage way.)
  • Compression fittings retaining pressure tube between control skirt and control are loose. (Examine and observe. Tighten fittings. Then lift pump above fluid level in sump and holding pump straight and vertical, place pump back into sump to retrap air in control skirt.)
  • Defective control switch. (Manually override control to check pump operations, if override is provided by manufacturer. If overridden control operates pump, but pump fails to function automatically, return pump to a service center. If override does not operate pump, pump motor is defective. Take pump to service center.


Pump operates but fails to deliver water or delivers insufficient water.



  • Impeller loose on shaft.(Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Tighten fasteners, replace key as required.)
  • Clogged or damaged impeller. (Remove screen and observe condition. Clean volute and impeller and remove any blockage. Take pump to Authorized Service Center.)
  • Water inflow excessive. (Observe source and amount of water inrush. Have larger sump and/or pump installed.)
  • Clogged screen or pump inlet. (Examine and observe. Clean screen.)
  • Air locked or air bound pump. Air bleed hole blocked. (Remove pump, disconnect power, connect to rated voltage and actuate control switch. Clean out air bleed hole or drill a 1/8" or 3/16" air bleed hole between pump discharge and check valve if required.)
  • Pipe discharge closed by obstruction or ice. (Examine and observe. Clean or snake discharge line.)
  • Inadequate discharge pipe diameter. (Measure discharge pipe and compare with manufacturer's suggested diameter (should be no smaller than pump discharge). Have larger diameter discharge piping installed.)
  • Defective, inoperative check valve or installed in wrong direction. (Observe arrow on check valve indicating direction of flow, install check valve in opposite direction if required. Check and clean gate of check valve.)
  • Loose shaft coupling. (Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Tighten coupling and set screws.)
  • Too high a static and friction head. (Measure vertical portion of discharge pipe (over 15 feet is excessive). If discharge pipe length is extremely long, the friction losses may exceed pump capacity. Observe number of pipe fittings and reducing bushings. Remove any reducing pipe fittings and elbows. Have higher head pump installed. Have larger diameter discharge piping installed.)
  • Motor running backwards. Disconnect power, remove pump from sump. Energy pump and observe impeller and shaft rotation. If single phase unit take pump to an Authorized Service Center for correction. If three phase unit have electrician reverse rotation by inverting two of the three power cables.)
  • Sump bottom soft and muddy. (Evacuate sump. Clean sump.)
  • Improperly sized pump. (Observe source and amount of water inrush. Have larger pump installed.)


Pump operates for a short time then stops.



  • Pump motor overload tripped. (Allow pump to cool for 5-10 minutes and reconnect, if overload trips again take corrective action. Have electrician or power company check & repair branch circuit voltage.)
  • Internal motor defect (Open motor winding, thermal overload defective, power cord open or damaged, centrifugal switch or relay defective or moisture. Remove pump, disconnect power, connect to rated voltage and actuate control switch. If it doesn't run return pump to Authorized Service Center.)
  • Pump motor overload tripped. (Allow pump to cool for 5-10 minutes and reconnect, if overload trips again take corrective action. Have electrician or power company check & repair branch circuit voltage.)
  • Internal motor defect( Open motor winding, thermal overload defective, power cord open or damaged, centrifugal switch or relay defective or moisture. Remove pump, disconnect power, connect to rated voltage and actuate control switch. If it doesn't run return pump to Authorized Service Center.)
  • Exceptionally high voltage: Call power cpmpany or electrician to repair circuit.
  • Exceptionally low voltage. Have line voltage checked and compare with manufacturer's specifications. Call electrician to repair circuit.
  • Impeller rubbing inlet plate or pump housing. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Return pump to Authorized Service Center.
  • Worn out or defective pump or motor bearings. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Return pump to Authorized Service Center. Replace pump bearing.
  • Water temperature too high. Measure water temperature. Add cold water to sump and test. Install a high temperature pump or reduce temperature of incoming water
  • Floats or weights improperly adjusted. Add water to sump and observe turn-on. Readjust control floats or weights.


Pump runs continuously



  • Automatic liquid level control switch defective. Manually operate control. Take pump to Authorized Service Center.
  • Impeller loose on shaft. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Tighten fasteners, replace key. Take pump to Authorized Service Center.
  • Water inflow excessive. Observe source and amount of water inrush. . Have larger pump installed or have larger sump basin and pump installed.
  • Clogged screen or pump inlet. Examine and observe. Disconnect power and clean screen.
  • Air locked or air bound pump. Disconnect power& remove pump. Clean air bleed hole or drill 1/8" or 3/16" air bleed hole between pump discharge and check valve.
  • Pipe discharge closed by obstruction or ice. Examine and observe. Clean or snake discharge line.
  • Inadequate discharge pipe diameter. Measure discharge pipe and compare with manufacturer's suggested diameter (should be no smaller than pump discharge). Have larger diameter discharge piping installed .
  • Defective or inoperative check valve. Check valve flapper. Clean check valve. Replace check valve as required.
  • Check valve installed in wrong direction. Observe arrow on check valve indicating direction of flow. Install check valve in opposite direction.
  • Float operation obstructed or restrained. Observe and check float or weight freedom. Readjust control floats or weights.
  • Floats or weights improperly adjusted. Add water to sump and observe turn-on. Readjust control floats or weights.
  • Float rod bent or obstructed by debris. Observe and check float or weight freedom. Readjust control floats or weights.
  • Too high a static and friction head. Measure vertical portion of discharge pipe (over 15 feet is excessive). If discharge pipe length is extremely long, the friction losses may exceed pump capacity. Observe number of pipe fittings and reducing bushings. Remove excessive reducing pipe fittings and elbows, increase discharge pipe or have larger pump installed.
  • Motor running backwards. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Take pump to Authorized Service Center.
  • Improperly sized pump. Observe source and amount of water inrush. Have larger pump installed.


Pump cycles too frequently



    Pump cycles on and off more than once a minute.
  • Water inflow excessive. Observe source and amount of water inrush. Have larger sump and pump installed.
  • Defective or inoperative check valve. Observe backflow of water from discharge. Check gate of check valve. Clean gate of check valve or install new check valve.
  • No check valve in high head installations. Examine and observe. Install check valve.
  • Floats or weights improperly adjusted. Add water to sump and observe turn-on. Readjust control floats or weights.
  • Sump basin size too small or pump to large for sump pit. Measure sump width and depth and compare with manufacturer's recommendations. Install smaller pump or install larger sump basin.


Pump turn on point & turn off point have changed



  • Float operation obstructed or restrained. Add water to sump and observe turn-on. Readjust control floats or weights.
  • Float rod bent or obstructed by debris. Observe and check float or weight freedom. Readjust control floats or weights.
  • Diaphragm control skirt lost trapped air. Manually override control to check pump operations, if override is provided by manufacturer. . Lift pump above fluid level in sump. Then holding pump straight and vertical, place pump back into sump to re-trap air in control skirt.
  • Compression fittings retaining pressure tube between control skirt and control are loose. Examine and observe. Tighten fittings. Then lift pump above fluid level in sump and holding pump straight and vertical, place pump back into sump to re-trap air in control skirt.
  • Pump not positioned firmly on bottom of sump. Disconnect power and check pump for stability. Readjust discharge piping and pump.


Pump operates very noisy.



    Squealing, hammering, grinding or excessive noise transmitted thru piping.
  • Impeller loose on shaft. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Tighten fasteners, replace key.
  • Impeller rubbing inlet plate or pump housing. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Take pump to an Authorized Service Center.
  • Worn out or defective pump or motor bearings. Examine and observe. Replace pump bearing.
  • Loose shaft coupling. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Tighten coupling and set screws.
  • Obstructed rotating parts. Disconnect power, remove pump from sump and observe for freedom of impeller and shaft rotation. Clean volute and impeller and remove any blockage.
  • Discharge plumbing connected directly to floor joists. Examine and observe. Readjust discharge piping and pump. Replace portion of discharge with rubber hose or install vibration isolator.
  • Pump not positioned firmly on bottom of sump. Disconnect power and check pump for stability. Readjust discharge piping and pump.
  • Gravel or stones on bottom of sump. Evacuate sump. Clean sump.


Sewer gas smell



  • Incorrect venting or plugged vent Check vent for restrictions
  • Improper gaskets and seals Remove cover and flanges. Clean all sealing surfaces. Replace foam gaskets and lightly grease O-rings and grommets. Reassemble

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