Understanding Sewer Pumps and Common Reasons They Fail

Sewer pumps play a crucial role in managing wastewater and sewage in homes and commercial buildings. When these pumps fail, the consequences can be messy, costly, and disruptive. Understanding why sewer pumps go bad helps homeowners and property managers avoid unexpected breakdowns and maintain a healthy plumbing system.

Sewer pump installed in a basement sump pit

What Sewer Pumps Do and Why They Matter

Sewer pumps move wastewater from lower to higher elevations, especially when gravity alone cannot carry sewage to the main sewer line. They are essential in basements, low-lying areas, or places where the sewer system is far below the building’s plumbing fixtures.

Without a working sewer pump, wastewater can back up into the home, causing damage and health hazards. These pumps work continuously or intermittently, depending on the system design, and must handle solids, grease, and other debris common in sewage.

Common Reasons Sewer Pumps Fail

Sewer pumps can fail for several reasons. Knowing these causes helps in early detection and prevention.

1. Clogging and Blockages

One of the most frequent problems is clogging. Sewer pumps handle solids and debris, but large or fibrous materials can jam the impeller or clog the intake screen. Items like wipes, sanitary products, grease buildup, and rags cause blockages.

Example: A homeowner flushed baby wipes down the toilet, which did not break down easily. These wipes accumulated and clogged the pump, causing it to overheat and fail.

2. Overheating Due to Continuous Running

If a pump runs too often or continuously, it can overheat and wear out prematurely. This happens when the pump is undersized for the volume of wastewater or when there is a leak or blockage causing constant cycling.

Tip: Check if the pump cycles on and off frequently. If it does, a larger pump or system adjustment may be necessary.

3. Electrical Issues and Power Failures

Sewer pumps rely on electricity to operate. Faulty wiring, tripped breakers, or power outages can stop the pump from working. Additionally, damaged float switches or control panels can prevent the pump from turning on or off correctly.

Example: A damaged float switch stuck in the “off” position caused a pump to stop working, leading to sewage backup.

4. Mechanical Wear and Tear

Like any mechanical device, sewer pumps experience wear over time. Bearings, seals, and impellers degrade, especially if the pump runs in harsh conditions or is not maintained regularly.

Regular inspection and replacement of worn parts extend the pump’s life.

5. Corrosion and Chemical Damage

Sewer pumps are exposed to corrosive substances in wastewater. If the pump materials are not resistant to these chemicals, corrosion can damage the pump housing and internal components.

Using pumps made from corrosion-resistant materials like stainless steel or thermoplastics helps prevent this issue.

How to Prevent Sewer Pump Failures

Preventing sewer pump failure involves proper use, regular maintenance, and timely repairs.

• Avoid flushing non-degradable items: Only flush human waste and toilet paper.

• Schedule regular inspections: Check the pump, float switch, and electrical connections every 6 to 12 months.

• Clean the pump and pit: Remove debris and buildup to prevent clogs.

• Test the pump operation: Run the pump periodically to ensure it cycles correctly.

• Install alarms: High-water alarms alert you to pump failure before backups occur.

  
  

Signs Your Sewer Pump May Be Failing

Recognizing early signs of pump failure can save time and money.

• Unusual noises: Grinding or rattling sounds may indicate mechanical problems.

• Frequent cycling: The pump turns on and off too often.

• Slow drainage or backups: Wastewater drains slowly or backs up into sinks or toilets.

• Pump runs continuously: The pump never shuts off.

• Water in the sump pit: Water level remains high despite pump operation.

  
  

If you notice any of these signs, call a professional plumber to inspect and repair the system.

Choosing the Right Sewer Pump

Selecting the correct pump size and type is vital. Pumps come in various capacities and designs, including submersible and pedestal models. Consider the following:

• Flow rate needed: How much wastewater the pump must handle.

• Type of solids: Some pumps handle larger solids better.

• Power supply: Ensure compatibility with your electrical system.

• Material durability: Choose corrosion-resistant materials for longevity.

  
  

Consulting with a plumbing expert helps match the pump to your specific needs.

Final Thoughts on Sewer Pump Maintenance

Sewer pumps are essential for safe and efficient wastewater management. They fail mainly due to clogging, overheating, electrical faults, mechanical wear, and corrosion. Preventive care, proper use, and timely repairs keep these pumps running smoothly.

If you experience any issues or suspect your sewer pump is failing, act quickly. Early intervention prevents costly damage and keeps your plumbing system healthy. Regular maintenance and choosing the right pump ensure reliable performance for years to come.