Check your sump pump every three months and before heavy rain
A sump pump sitting idle for months can fail the moment water starts rising in your basement. The motor may not start, the discharge pipe may be clogged, or the float switch that triggers the pump may be stuck. A quick hands-on check takes 15 minutes and catches problems before they flood your basement.
The best time to check is before the wet season in your area — spring in most places, fall in others. Check again every three months during the season, and always before a forecast heavy rain. If you have not looked at your pump since last year, check it today.
Key Takeaways
- Pour water into the sump pit until the float rises and the pump turns on — if it does not start, the motor or switch is broken and needs replacement.
- Listen for the pump to run smoothly without grinding or squealing; strange noises mean internal damage and warrant a service call.
- Follow the discharge pipe from the pump to where it exits your house and make sure water actually flows out when the pump runs.
- Check that the pump sits level in the pit and the float moves freely without hitting the pit walls or the pump itself.
- Keep the pit clear of debris, sediment, and rags that can jam the intake screen or clog the discharge line.
Test the pump by filling the pit with water
The most reliable check is a manual test. Go to your sump pit — usually in the basement, crawlspace, or lowest point of the house — and look inside. You should see the pump sitting in the bottom, a float arm or ball attached to it, and a discharge pipe running upward and out of the house.
Use a bucket to pour water into the pit slowly. Watch the float as the water level rises. When the water reaches the float's trigger point, the pump should turn on. You will hear the motor start and feel vibration. If nothing happens after the water is several inches deep, the pump is not working and needs to be replaced.
Let the pump run for 30 seconds while you listen. The sound should be a steady hum or low rumble. If you hear grinding, squealing, or rattling, the motor or internal parts are damaged. Stop the test and call a plumber or pump specialist.
Follow the discharge pipe to confirm water is leaving the house
While the pump is running, walk outside and find where the discharge pipe exits your house. This is usually a white or black plastic pipe coming out of the foundation, often near a basement window or corner. Water should be flowing out of the end of this pipe — you should see it splashing or hear it running.
If no water comes out, the pipe is clogged. This can happen from sediment buildup, ice in winter, or debris sucked up from the pit. Turn off the pump and let the pit drain. Then disconnect the discharge pipe at the pump (usually a slip-fit connection you can pull apart by hand) and look inside for blockage. Flush it with a garden hose or use a plumbing snake to clear it.
Make sure the discharge pipe slopes downward and does not loop upward before exiting — water can get trapped in a loop and freeze or back up into the pit. The pipe should also drain at least 4 to 6 feet away from your foundation so water does not pool against the house.
Check the float and intake screen for obstructions
After the pump stops, look at the float. It should move freely up and down on its arm or rod without hitting the pump body or the pit walls. If it is stuck or rubbing, it will not trigger the pump when water rises. Gently move it by hand to make sure it swings smoothly.
Look at the intake screen at the bottom of the pump — a mesh or perforated cover that prevents debris from entering the motor. If it is clogged with sediment, silt, or lint, the pump will not draw water efficiently and may overheat. Use a soft brush or cloth to clean it gently. Do not use a hard tool that could damage the screen.
Check the pit itself for debris. Rags, gravel, leaves, or sediment can jam the pump or clog the discharge line. If the pit is dirty, use a wet-dry vacuum to clean it out, or bail out the water and sweep the bottom. A clean pit means fewer clogs and longer pump life.
Inspect the power cord and electrical connection
Look at the power cord running from the pump to the outlet. It should not be cracked, frayed, or sitting in standing water. If the cord is damaged, do not use the pump — water and electricity are a dangerous combination. Replace the cord or the pump itself.
Make sure the pump is plugged into a GFCI outlet (ground-fault circuit interrupter). This outlet has a test and reset button on its face and cuts power when ready if there is a short circuit. If your pump is plugged into a regular outlet, ask an electrician to install a GFCI outlet. This is a safety requirement in most building codes.
If the pump has a backup battery or backup pump system, check that the battery is charged and the backup pump is also plugged in and ready. During a power outage, the backup takes over and keeps water from backing up into your basement.
Know when to call a professional instead of troubleshooting
If the pump does not turn on after you pour water into the pit, do not keep testing it. The motor may be burned out or the switch may be broken. Call a plumber or sump pump specialist to replace it. A new pump costs less than the water damage that happens when the old one fails.
If the pump runs but makes grinding or squealing sounds, stop using it. These noises mean the bearings are worn or the impeller is damaged. Running it further will cause it to seize. Replacement is the safest option.
If water backs up into the pit faster than the pump can remove it, the pump may be undersized for your water table, or the discharge line may be too small. A professional can measure the flow rate and recommend an upgrade if needed.
Set a reminder to check every three months
Write the check date on your calendar or set a phone reminder for every three months during the wet season. A quick 15-minute check prevents the panic of discovering a failed pump during a storm. Many homeowners find it helpful to check in spring, early summer, fall, and before winter — four times a year.
Keep a straightforward log of what you checked and what you found. Note the date, whether the pump started, whether water flowed out the discharge pipe, and any sounds or problems. If you ever need to call a professional, this log helps them understand the pump's history.
Frequently Asked Questions
How often should I test my sump pump?
Test it every three months during the wet season in your area, and always before heavy rain is forecast. If you live in a place with year-round groundwater, test it four times a year. A quick manual test takes 15 minutes and catches problems before they cause flooding.
What if my pump runs but water still backs up into the basement?
The pump may be too small for the amount of water entering the pit, or the discharge line may be clogged or too small. You may also have a second sump pit or a crack in the foundation letting in more water than the pump can handle. A plumber can measure the water flow and recommend whether you need a larger pump or a second pump.
Can I use a regular outlet for my sump pump?
No. Sump pumps must be plugged into a GFCI outlet, which cuts power when ready if there is a short circuit. A regular outlet does not have this protection and creates a shock hazard around water. If your pump is on a regular outlet, ask an electrician to install a GFCI outlet.
What does it mean if the float is stuck?
A stuck float will not rise with the water level, so the pump will not turn on when it should. The float may be jammed against the pump body, the pit wall, or debris. Gently move it by hand to free it. If it stays stuck, the float arm may be bent and need replacement.
Is it normal for the pump to make noise?
A steady hum or low rumble is normal. Grinding, squealing, or rattling sounds mean the motor or internal parts are damaged. Stop using the pump and call a professional. Running a damaged pump can cause it to seize completely and leave you without drainage during a heavy rain.