A Guide to Sump Pump Repair and Maintenance

A properly functioning sump pump is crucial for preventing water damage and flooding in basements and crawlspaces. However, like any mechanical device, sump pumps can eventually malfunction or fail. Being able to troubleshoot common sump pump problems and perform basic maintenance can help ensure your sump pump continues working when you need it most. This comprehensive guide provides tips for repairing and maintaining your sump pump system.

How a Sump Pump Works

Understanding the basic operation of a sump pump helps troubleshoot problems. Here’s a quick overview:

Sump pit – This is a hole or basin in the lowest part of the basement that collects water. The sump pit may be below the basement floor or embedded in the concrete.
Sump pump – This pump activates when water in the sump pit reaches a certain level. It pumps the water out through a discharge pipe.
Float switch – This mechanism turns the sump pump on when the water rises high enough to lift the float. It turns off the pump when the water drains low enough to lower the float.
Discharge pipe – This pipe carries water from the sump pump out of the house, usually through the foundation wall or to a distant drain.
Check valve – This device permits water to flow one way only, preventing backflow through the discharge pipe after the pump shuts off.

Knowing how these components interact helps diagnose sump pump failures. Next, we’ll look at the most common problems and solutions.

Troubleshooting Common Sump Pump Problems

Several issues can prevent a sump pump from working properly. Here are some of the most frequent problems and repairs:

Pump Not Turning On

If the sump pump won’t turn on at all, start by checking these areas:

Power supply – Confirm the pump is plugged in and that the outlet has power. Try plugging in a lamp to test the outlet. Reset any tripped circuit breakers.
Float switch – Remove debris stuck under the float. Adjust the switch up or down if needed. Test it by manually lifting the float to see if the pump turns on. Replace a defective float switch.
Impeller – Use a long, thin object to free a stuck impeller. If it’s still stuck, the pump may need to be disassembled to access the impeller.
Motor – If the impeller spins freely but the pump doesn’t run, the motor is probably burned out. Replace a defective motor.
Wiring – Inspect wires for damage. Check connections. Bypass any switches to test the pump directly. Faulty wiring will need to be repaired or replaced.
Fuse – If equipped, check the fuse in the pump’s power cord. Replace blown fuses.

Pump Runs But Doesn’t Pump Water

A pump that runs but moves little or no water likely has a clog or mechanical problem:

Discharge pipe – Disconnect the pipe to remove clogs at either end. Flush debris from the pipe. Replace it if severely clogged.
Impeller – As mentioned, use a tool to free a stuck impeller. Remove and clean out the volute casing if needed.
Check valve – A stuck closed or clogged check valve prevents water discharge. Clean or replace the valve.
Worn impeller – Impellers eventually wear out, reducing pumping efficiency. Replace the impeller if worn.
Incorrect motor rotation – Test that the impeller rotates in the proper direction. Reverse wires to change direction if incorrect.

Pump Turns On and Off Frequently

Frequent cycling on and off can indicate:

Float switch – Adjust its height if it’s turning on/off prematurely. Replace a defective switch.
Check valve failure – A faulty check valve allows water to flow back into the pit. Replace the check valve.
Clogged discharge – Partial clogs hinder water flow, causing the pump to reactivate soon after turning off. Inspect and clean discharge piping.
High water table – If the water table around the house is very high, the sump pit may refilled rapidly. Not much can be done in this case.
LeakingPit – Cracks, porous concrete, or loose pipe joints allow water to re-enter the pit. Repair any leaks in the sump pit.

Pump Runs With No Water Discharge

If the pump runs continuously but moves no water, it indicates:

Severed discharge pipe – Broken pipes or blown-off connections prevent water ejection. Repair ruptured pipes and reconnect loose joints.
Impeller blocked – As covered, free stuck impeller. If necessary, remove and clean out the pump housing.
Clogged discharge – A completely blocked discharge line causes no water flow. Snaking the discharge pipe may clear very severe clogs.

Loud Operation

Typical causes of loud or noisy pump operation are:

Trash stuck in impeller – Small stones, sediment, or debris in the pump housing can create noise. Clean out the pump volute.
Worn bearings – Age and wear causes bearings and bushings to become noisy. Replace defective bearings.
Piping issues – Loud clanking or hammering sounds may come from loose, unsupported, or improperly installed discharge piping. Inspect and re-support pipes as needed.
High water flow – As the pump ejects water at high volume, turbulence and velocity can create noise. Not much can be done in this case.

Sump Pump Maintenance

Routine maintenance helps prevent many sump pump problems and keep your system working properly. Here are some key maintenance tips:

Clean the Sump Pit

Check a few times a year for dirt, debris, oil, and sediment buildup.
Remove any debris that could clog the pump or float switch.
Scrub pit walls with a long brush and flush water to remove grime.

Check the Discharge Pipe

Inspect the discharge pipe annually for cracks or obstructions.
Flush with water if partially clogged. Replace severely clogged plastic pipe.
Make sure all joints are tight to avoid leaks.

Test the Pump

Fill the sump pit with water and verify the pump turns on at the appropriate level.
Confirm adequate flow volume while running.
Make sure the pump turns off when the water is pumped down.
Repeat this test 1-2 times per year.

Change the Check Valve

Inspect the check valve annually and replace every 3-5 years.
Listen for clicking as water flows to confirm proper operation.
Replace if stuck open or closed, warped, or cracked.

Clean the Impeller and Volute

Remove debris around the impeller by flushing and scrubbing.
Disassemble the pump housing if needed to fully clean the impeller and casing.

Inspect the Float Switch

Wipe off dirt and oil from floats encrusted with grime.
Adjust floats that stick or turn on/off prematurely.
Replace broken or inaccurate float switches.

Maintain Power Supply

Unplug and inspect the pump power cord annually.
Check that the outlet is grounded and connections are tight.
Replace damaged or frayed electrical wiring.

Installing a New Sump Pump

There comes a time when an old pump is beyond repair and needs replacement. Here are some tips for installing a new sump pump correctly:

Choose a pump with adequate pumping capacity (gallons per hour) and lift height for your application.
Set the float switch so the pump turns on when water reaches 8-12 inches in the sump pit.
Position the pump as high off the bottom of the pit as possible to avoid sediment intake.
Mount the pump and float switch securely using the manufacturer’s recommended method.
Use rigid PVC pipe for the discharge line if possible for long-lasting service.
Install a union discharge fitting so the pump can be removed easily if needed.
Include a check valve in the discharge piping to prevent backflow into the pit.
Make sure the discharge pipe is the appropriate diameter for the pump’s capacity.
Slope the discharge pipe upward toward the exit point if possible to improve flow.
Secure discharge piping with braces and hangers to reduce vibration noise.

Signs It’s Time for a New Pump

Consider replacing an old or malfunctioning sump pump if you notice:

Frequent cycling on and off without moving water.
The pump struggling to empty the sump pit.
Water overflowing the sump basin when the pump runs.
Loud whining, grinding or clicking sounds.
Corroded, cracked or otherwise deteriorating parts.
Older pump technologies from the 1980s or earlier.

Newer pump models are more energy-efficient, quieter, and more reliably handle high volumes of water. Investing in a new pump can provide peace of mind and protect against costly water damage.

Troubleshooting Tips

Here are some additional troubleshooting tips for diagnosing and repairing sump pump systems:

If the pump runs for long periods without shutting off, check for leaks allowing water to continually seep into the pit.
Pumps that turn on without the float activating may have faulty switch wiring.
Plugging the pump to an outlet further away can determine if the issue is low voltage due to extension cords.
For pit overflows, determine if the pump capacity is insufficient for incoming water volume.
Funny smells from the sump pit could indicate contamination requiring pit cleaning.
Keep a spare pump, float switch, and check valve on hand so replacements are readily available when needed.
Note the age of various components to help diagnose when wear may be causing problems.
Test pump and disharge piping before finishing basement living spaces to find and correct issues.

Preventing Sump Pump Failure

Regular maintenance goes a long way, but other tips can also minimize sump pump problems:

Install redundant battery backup pumps in case of power outages.
Use a water alarm to warn of rising water before it overflows.
Have replacements ready for parts that commonly fail, like check valves.
Consider a cast iron or stainless steel pump for longer service life.
Keep the sump pit covered to reduce debris entry.
Divert drainage away from the house foundation when feasible.
Make sure the sump pump discharges away from the house.
Store valuables in watertight containers in case of flooding.

With proper installation and maintenance, a quality sump pump should provide 5-10 years of reliable service. But being prepared to act at the first sign of trouble can help avoid extensive water damage.

FAQs about Sump Pump Repair and Maintenance

How do I unplug a clogged sump pump discharge line?

Use a drain snake or auger to try clearing obstructions in the discharge pipe. Or disconnect the pipe and use a pressurized hose to flush clogs. Severely clogged plastic discharge tubing often needs complete replacement.

Why does my sump pump run constantly?

Continuous running indicates water is entering the pit faster than the pump can eject it. Look for sources of leaks near the foundation allowing groundwater intrusion. A pump past its pumping capacity may also run nonstop before overflowing.

How can I quiet a noisy sump pump?

Check for debris in the impeller causing rattling vibrations. Sediment buildup in the pump housing can also create noise. Securely mounting the pump and bracing discharge pipes helps reduce normal operational noise. Replace defective bearings or bushings causing loud grinding or squealing sounds.

Where should the float switch be positioned?

The float switch should activate when water reaches 8-12 inches in the sump pit. This gives the pump time to run and eject water before overflowing. Adjust the switch height by sliding it up or down the pump pipe accordingly.

How do I know if my pump impeller is clogged or stuck?

An impeller that’s jammed or blocked by debris prevents water ejection. The pump may run continuously with little or no water discharge. Try freeing the impeller with a tool. If unsuccessful, disassemble the pump to access and clear the impeller.

Conclusion

Regular sump pump inspection, testing, and maintenance prevents many common failures that can lead to water damage in basements. While pumps eventually wear out and need replacing, addressing minor repairs quickly extends their useful life. Knowing when professional help is required also keeps your sump pump working reliably to protect your home. With this guide’s troubleshooting tips for sump pump repair and maintenance, you can take proactive steps to ensure your unit operates when needed.