Test your pump every three months and clean the intake screen monthly
A sump pump needs two things to work when water arrives: power and a clear path for water to enter. Test it by pouring a bucket of water into the pit — the pump should turn on within seconds and drain the water completely. If it hesitates, cycles on and off rapidly, or makes grinding sounds, something is wrong and needs attention before the next heavy rain.
The intake screen (the part that sits in the water) clogs with sediment, leaves, and debris. Once a month, especially after storms, lift the pump slightly and rinse the screen with a garden hose. A blocked screen forces the motor to work harder and shortens its life. If your pit is in a basement or crawlspace, mark a calendar reminder so you do not skip this step.
Key Takeaways
- Test your pump monthly by pouring water into the pit and watching it drain; if it does not respond within seconds, the motor or float switch needs repair.
- Clean the intake screen monthly to prevent sediment buildup, which forces the motor to work harder and can cause premature failure.
- Check the discharge line outside the house every season to make sure water flows away from the foundation, not back toward it.
- Replace the pump every 5 to 10 years depending on how often it runs; a pump that cycles constantly is nearing the end of its life.
- Keep the pit itself clean by removing standing water, leaves, and debris that can jam the float switch or clog the intake.
Clear the discharge line so water actually leaves your foundation
The discharge line is the pipe that carries water away from your house. In winter, ice can block it. In summer, debris can clog it. Walk outside after rain and check whether water is flowing out of the discharge opening — if it is trickling or not flowing at all, the line is partially blocked.
If the line is clogged, disconnect it from the pump (usually a slip fitting you can hand-tighten), hold it up to a light, and look through it. Leaves, sediment, and mineral deposits are common culprits. Flush it with a garden hose from the house end. If water does not flow freely, you may need to disconnect the line at both ends and run a plumbing snake through it, or replace the section that is blocked.
Check that the discharge opening points downhill and away from your foundation — ideally at least 10 feet away. If water is draining back toward the house, reposition the line or add an extension. A pump that works perfectly but drains water back into the foundation defeats the whole purpose.
Replace the float switch if the pump will not turn on
The float switch is a small arm or ball that rises with water level and triggers the pump to start. Over time, it gets stuck, corroded, or straightforward wears out. If you pour water into the pit and the pump does not turn on, the float switch is usually the problem, not the motor.
Most float switches can be replaced without removing the entire pump. They screw or clip onto the pump body and cost between $20 and $60. Before you buy a replacement, check your pump's model number (usually stamped on the motor housing) and order the exact switch for that model — float switches are not universal.
If the pump turns on but will not turn off, the float switch is also the culprit. It is stuck in the up position and keeps signaling the motor to run. Tap the switch gently with a wrench handle to see if it frees up. If tapping does not work, replace it.
Inspect the pit itself for debris and standing water
The pit is where water collects before the pump removes it. If the pit stays wet between rainstorms, bacteria and mold grow, and the pump sits in stagnant water that corrodes metal parts. After the pump drains the pit, there should be no standing water left behind.
If water remains, the pump may be undersized for your home, or the pit may have a drainage problem. Check whether the pit has a drain line running to a sump or storm drain — if it does, make sure that line is not clogged. If the pit has no drain and water sits there for days, you may need a larger pump or a second pump.
Remove leaves, dirt, and debris from the pit regularly. These materials can jam the float switch or get sucked into the intake screen. If your pit is in a basement, cover it with a grate or lid to keep debris out and reduce odors.
Check the backup power system before storm season
Many sump pumps have a battery backup that runs the pump if the power goes out. This backup is useless if the battery is dead or disconnected. Before heavy rain season, test the backup by unplugging the pump from the wall outlet — the battery should power the pump and drain water from the pit.
Battery backups typically run the pump for 6 to 8 hours on a full charge. If your area loses power for longer than that during storms, the pit will overflow. Check the battery terminals for corrosion (white or blue-green powder) and clean them with a wire brush if needed. Replace the battery every 3 to 5 years, even if it still works — old batteries fail suddenly when you need them most.
Know when to replace the pump instead of repair it
A sump pump typically lasts 5 to 10 years. If your pump is older than that and starts acting up, replacement is usually cheaper than repair. A new pump costs $300 to $800 installed, depending on the type and your location. A repair call costs $150 to $300 just for diagnosis, and the part may cost another $100 to $400.
Signs that replacement is near: the pump cycles on and off constantly (even when no rain has fallen), it makes loud grinding or squealing noises, or it takes longer than a few seconds to respond to water. A pump that runs constantly is working too hard and will fail soon. A pump that is slow to start may have a failing motor or a float switch that is sticking.
If you have had the pump for 7 years or more and it needs a repair, ask the technician whether a new pump makes sense. Sometimes it does. Sometimes the repair is straightforward and the pump will run for another few years.
Frequently Asked Questions
How often should I test my sump pump?
Test it at least once every three months by pouring a bucket of water into the pit and watching it drain. If you live in an area with heavy rain or your pump runs frequently, test it monthly. A pump that has not been tested in months may fail when you need it most.
What does it mean if my pump is running constantly?
Constant running usually means water is entering the pit faster than the pump can remove it, or the pit has a drainage problem. It can also mean the float switch is stuck. Check the discharge line first to make sure water is actually leaving the house. If the line is clear and water is still pooling, the pump may be undersized or the pit may need a drain.
Can I use a regular extension cord with my sump pump?
No. Sump pumps draw significant power and generate heat. A regular extension cord can overheat and cause a fire. Use a heavy-duty, grounded extension cord rated for the pump's amperage, or better yet, have an electrician install a dedicated outlet near the pump. Check your pump's manual for the correct cord gauge.
What should I do if my pump smells bad?
A foul smell means bacteria or mold is growing in the pit, usually because water is sitting there too long between pumping cycles. Make sure the pit drains completely after the pump runs. If water remains, the pump is too small or the pit has a clogged drain line. Clean the pit and consider adding a small amount of bleach to kill bacteria, but do not make this a regular practice.
Is it normal for my sump pump to run during light rain?
Yes, if your foundation naturally collects groundwater. The pump should run for a few minutes and then stop. If it runs for hours during light rain, the pump may be undersized, or water is entering the pit faster than expected. This is not an emergency, but it means the pump is working harder than ideal and may wear out sooner.