Common Centrifugal Pump Problems and How to Fix Them

Centrifugal pumps are among the most widely used fluid-handling equipment across industries such as water treatment, chemical processing, power generation, HVAC, oil & gas, and manufacturing. Their simple structure, continuous flow, and relatively low maintenance requirements make them a preferred choice for many applications.

However, despite their reliability, centrifugal pumps are not immune to operational issues. Problems such as loss of pressure, cavitation, vibration, leakage, and overheating can significantly reduce efficiency, increase downtime, and shorten service life if not addressed promptly.

This article explores the most common centrifugal pump problems, explains their root causes, and provides practical solutions based on real-world operating conditions. Whether you are a maintenance engineer, plant manager, or procurement specialist, this guide will help you improve pump reliability and performance.

1. Centrifugal Pump Losing Flow or Pressure

One of the most frequently reported centrifugal pump problems is insufficient flow rate or pressure. The pump may run, but it fails to deliver the expected performance.

Common Causes

• Air trapped in the suction line

• Clogged impeller or suction strainer

• Incorrect pump speed

• Excessive system resistance

• Worn impeller or internal components

How to Fix It

Start by checking the suction line for air leaks or improper priming. Ensure the pump is fully primed before startup. Inspect the impeller and suction strainer for debris, sediment, or scaling, especially in water treatment and industrial process applications.

Verify that the pump is operating at the designed speed and that the motor is delivering sufficient power. If the system curve has changed due to pipe modifications or valve restrictions, reassess pump selection. In older pumps, impeller wear can significantly reduce hydraulic efficiency and may require replacement.

2. Cavitation in Centrifugal Pumps

Cavitation is a destructive phenomenon caused by vapor bubble formation and collapse inside the pump. It often produces a crackling or gravel-like noise and can severely damage the impeller.

Common Causes

• Insufficient Net Positive Suction Head (NPSH)

• High fluid temperature

• Excessive suction lift

• Blocked or undersized suction piping

• Pump operating far from best efficiency point (BEP)

How to Fix It

Ensure that the available NPSH (NPSHa) exceeds the required NPSH (NPSHr) specified by the manufacturer. Reduce suction pipe length, minimize bends, and increase pipe diameter if necessary. Lowering fluid temperature or repositioning the pump closer to the fluid source can also help.

Operating the pump near its BEP is critical. In our own experience at Kenflo, we often see cavitation issues linked not to pump quality, but to mismatched system design. Proper pump selection based on actual operating conditions plays a key role in cavitation prevention.

3. Excessive Vibration and Noise

Unusual vibration and noise are early warning signs of centrifugal pump problems and should never be ignored.

Common Causes

• Shaft misalignment

• Imbalanced impeller

• Bearing wear or failure

• Loose foundation or mounting bolts

• Cavitation or hydraulic instability

How to Fix It

Check pump and motor alignment using laser or dial indicators. Inspect bearings for wear and lubricate them according to manufacturer guidelines. Tighten all foundation bolts and ensure the baseplate is properly grouted.

If vibration persists, conduct a vibration analysis to identify frequency-related issues. Regular condition monitoring can prevent catastrophic failures and unplanned shutdowns.

4. Centrifugal Pump Overheating

Overheating can affect both the pump and motor, leading to seal damage, bearing failure, and reduced efficiency.

Common Causes

• Operating at low flow or dead-head conditions

• Excessive internal friction

• Insufficient lubrication

• Blocked cooling passages

• Electrical motor issues

How to Fix It

Avoid running the pump against a closed discharge valve for extended periods. Ensure proper lubrication schedules are followed, and verify that cooling systems are functioning correctly.

From a design perspective, selecting pumps with appropriate clearances and materials helps manage thermal loads, especially in high-temperature industrial applications.

5. Leakage from Mechanical Seals or Packing

Seal leakage is a common maintenance issue and often leads to secondary damage if left unresolved.

Common Causes

• Improper seal installation

• Dry running conditions

• Misalignment

• Excessive pressure or temperature

• Seal face wear

How to Fix It

Always follow proper installation procedures and ensure the pump is fully primed before startup. Replace worn mechanical seals promptly and verify that seal materials are compatible with the pumped fluid.

In chemical and corrosive applications, seal selection is critical. At Kenflo, we focus on matching seal design and materials to actual operating conditions rather than relying on generic solutions.

6. Bearing Failure in Centrifugal Pumps

Bearings are essential for smooth pump operation, and their failure often results in severe downtime.

Common Causes

• Inadequate or excessive lubrication

• Contaminated lubricant

• Shaft misalignment

• Excessive radial or axial loads

• High vibration levels

How to Fix It

Use the correct type and amount of lubricant recommended by the manufacturer. Protect bearings from contamination by ensuring proper sealing. Regular inspections and predictive maintenance techniques such as temperature and vibration monitoring are highly effective in preventing bearing failure.

7. Centrifugal Pump Not Priming

A centrifugal pump that fails to prime cannot generate suction and will not deliver fluid.

Common Causes

• Air leaks in suction piping

• Foot valve malfunction

• Incorrect installation height

• Empty suction line

How to Fix It

Inspect all suction connections and gaskets for leaks. Ensure the foot valve is functioning properly and that the pump is installed within allowable suction lift limits. In some systems, installing an automatic priming device may be beneficial.

8. Reduced Pump Efficiency Over Time

Gradual efficiency loss often goes unnoticed but leads to increased energy consumption and operating costs.

Common Causes

• Internal wear and corrosion

• Impeller erosion

• Increased system resistance

• Operating far from BEP

How to Fix It

Conduct periodic performance testing to compare actual pump curves with original specifications. Replace worn components and reassess system requirements. Energy-efficient centrifugal pumps and variable frequency drives (VFDs) can significantly improve long-term performance.

Preventive Maintenance: The Key to Reliable Operation

Many centrifugal pump problems are preventable with a structured maintenance strategy. Regular inspection, condition monitoring, and proper documentation can extend pump life and reduce total cost of ownership.

Based on our long-term field experience, we believe that correct selection, proper installation, and routine maintenance are more important than simply choosing the most expensive pump. This philosophy guides how we approach pump solutions at Kenflo—focusing on reliability, efficiency, and real operating conditions rather than marketing claims.

Conclusion

Centrifugal pumps remain a cornerstone of industrial fluid handling, but their long-term performance depends heavily on correct selection, proper installation, and consistent maintenance. Understanding common centrifugal pump problems—such as cavitation, vibration, leakage, and efficiency loss—enables operators to take proactive measures before minor issues escalate into major failures.

By combining sound engineering practices with preventive maintenance and well-designed systems, users can achieve stable operation, lower energy consumption, and extended pump service life. From our perspective at Kenflo, reliable centrifugal pump performance is not just about the equipment itself, but about how well the pump matches real operating conditions. That is why we focus on practical design, appropriate material selection, and application-oriented solutions in our centrifugal pumps—helping customers build systems that operate efficiently and consistently over time.