Centrifugal Pump Troubleshooting Guide
This “TROUBLESHOOTING” information is intended to guide in the general determination of pump
problems and their solutions.

Little or no discharge

• Casing not initially filled with water. (Fill pump casing)
  
• Total head too high. (Shorten suction and/or head)
  
• Suction lift too high, or too long (Lower suction lift, install foot valve and prime, or shorten length of
  suction line)
  
• Foot valve or suction line not submerged deep enough in water (Submerge lower in water‐‐at least 3
  feet)
  
• Impeller damaged (Replace impeller)
  
• Suction piping too small (Increase to pump inlet size or one size larger)
  
• Motor wired incorrectly (Check wiring diagram)
  
• Casing gasket or "O" ring leaking (Replace)

Loss of suction

• Air leak in suction line (Repair & replace)
  
• Suction lift too high (Lower suction lift, install foot valve and prime)
  
• Clogged foot valve check valve or strainer (Unclog)
  
• Defective foot valve or check valve (Replace)
  

Motor Overheats and Shuts Off (Overload)

• Motor voltage does not match power supply voltage (Check motor connection against wiring diagram
  on the motor nameplate and against the power supply voltage)
  
• Impeller is rubbing against pump case or not turning freely (Dismantle pump, unclog or replace the
  impeller)
  
• Low voltage at the motor (Make sure electrical connections are tight)

Pump leaks at shaft

• Worn mechanical seal (Replace mechanical seal)
  
• Mounting plate or foundation not rigid enough (Reinforce)
  
• Foreign material in pump (Dismantle pump and clean)
  
• Impeller damaged (Replace impeller)
  
• Worn motor bearings (Replace bearings)

Pump will not deliver water or develop pressure

• No priming water in casing (Fill pump casing)
  
• Mechanical seal leaking (Replace mechanical seal)
  
• Leak in suction line (Repair or replace)
  
• Discharge line is closed and priming air has nowhere to go (Open)
  
• Pump is down (Replace worn parts)
  
• Foot valve or check valve is leaking (Replace valve)

Pump will not prime

• No priming water in casing (Fill pump casing)
  
• Mechanical seal leaking (Replace mechanical seal)
  
• Leak in suction line (Repair or replace)
  
• Suction line or valve is closed (Open)
  
• Foot valve or check valve is leaking (Replace valve)
  
• Suction screen clogged (Clean or replace)

Pump will not start or run

• Improperly wired (Check wiring against diagram on motor)
  
• Stone or foreign object lodged in impeller (Dismantle pump and remove foreign object)
  
• Motor shorted out (Replace motor)
  
• Thermal overload has opened circuit (Allow unit to cool, restart after reason for overload has been
  determined