How to Test a Sump Pump

Red Seal Plumber

Andrew

Testing takes less than 15 minutes, but doing it carefully can save you from major flooding damage.

Print Guide Pin Guide

Prep Time 5

Work Time 10

Total Time 15

Difficulty Intermediate

Cost $0 - $30

Frequency Annually

Tools & Equipment

1 Bucket
1 Flashlight
1 Gloves and safety glasses
1 Small brush or cloth

Parts & Supplies

$5 1 Mild cleaner (vinegar solution works well)
$40-90 1 Replacement check valve (optional if the current one fails)

Instructions

Safety first
Unplug the sump pump or turn off the breaker before starting. This prevents electrical shock while you’re working near water. Always wear gloves and safety glasses.
⚠️ Danger: Never reach into the pit while the pump is plugged in. Electricity and water together can be deadly.
Inspect the float switch
Look inside the pit and gently lift or move the float. It should move freely up and down without getting caught. The float switch is what triggers the pump.
⚠️ Stop here if the float is stuck, broken, or tangled — forcing it can damage the mechanism. Call a plumber if it won’t move.
Check the power source
Plug the pump into a GFCI-protected outlet and make sure the cord is in good condition. If you have a battery backup, confirm it’s fully charged.
⚠️ Danger: If the cord is cracked, frayed, or warm to the touch, don’t use the pump — it’s an electrical hazard.
Add water to the pit
Fill a clean bucket with water and slowly pour it into the sump pit until the float rises. Watch for the pump to turn on within seconds.
⚠️ Stop if the pump hums but doesn’t discharge water. This could mean the impeller is jammed or the motor is failing.
Confirm the pump is discharging
Stand beside the sump pit while the pump is running. Watch the water level in the pit — it should drop steadily as the pump activates. At the same time, listen for the sound of water moving through the discharge pipe. You should hear the check valve click or open as water passes through, followed by the whoosh of water flowing in the pipe.
⚠️ Stop if the water level does not go down or if you hear only humming with no water movement. This may mean the impeller is jammed, the discharge line is blocked, or the pump has failed. Call a plumber immediately.
Note: In most Canadian cities, sump pumps discharge into the storm sewer system. In rural areas, they may discharge to a yard or drainage ditch.
Confirm the shutoff
When the pit empties, the float should drop back down and the pump should shut off smoothly. This shows the switch is working both ways.
⚠️ Stop if the pump keeps running nonstop. That usually means a float switch or check valve problem, and it risks burning out the motor.
Clean the pit and pump
Once the test cycle is complete, unplug the pump again. Use a small brush or cloth to clean the pump’s inlet screen and clear out any debris, sludge, or gravel from the pit. Most residential sump pumps are submersible, so rinsing them with clean water will not hurt them — in fact, a good wash helps keep the impeller and screen clear.
⚠️ Important: If your sump pit is very deep, large, or has heavy buildup, do not attempt to clean it yourself. Deep pits can be dangerous confined spaces and may require a professional crew with a vacuum truck to remove the material safely.
👉 Always replace the pit cover after cleaning to prevent falls or new debris from entering.
Inspect the check valve
Locate the check valve on the discharge pipe, usually just above the sump pit. The check valve prevents water from flowing back into the pit after the pump shuts off.
Basic test (all homeowners): After a pump cycle, listen for the valve to click shut and confirm that the pit water level does not rise again. If you hear gurgling or see the water level return, the valve may be failing.
Visual inspection (only if installed to code with a union fitting): Some sump systems include a union fitting above the pit that allows the pipe to be disconnected safely. With this setup, you can remove the valve for inspection and cleaning.
Stop if you see heavy backflow or cannot disconnect the valve safely. A faulty or inaccessible check valve should be serviced by a licensed plumber.
⚠️ Important: Many Canadian cities require sump pump installations to follow plumbing code, which includes a union fitting for service. If your system does not have one, do not attempt to cut or remove the pipe yourself, call a plumber.
Restore power and retest
Plug the pump back in and run one more bucket test to make sure everything works smoothly after cleaning.
⚠️ Danger: Don’t leave the pit cover off — an open pit is a fall hazard and allows debris to enter.

Notes

Always reconnect to a GFCI outlet.
Test more often in flood-prone or high water table areas.
Document test dates for insurance purposes.