Start with the simple checks
Confirm the pump is plugged into a working outlet and that the GFCI has not tripped. Check the breaker. Lift the float by hand to see whether the pump starts. If it does, the float or its switch is the problem.
Look for debris in the pit that could jam the float, and check that the discharge line is not frozen or kinked. A running pump that does not move water may have a blocked intake or a failed check valve.
Symptoms and likely causes
Use this table to narrow the problem. Anything involving a burning smell or a tripped breaker is a stop-and-call.
| Symptom | Likely cause | Repair or replace |
|---|---|---|
| Pump does not start | No power, tripped GFCI or stuck float. | Often repair. |
| Runs but moves little water | Clogged intake, worn impeller or blocked discharge. | Clean or replace. |
| Runs constantly | Stuck float, failed check valve or high groundwater. | Repair or replace check valve. |
| Short cycles | Check valve failure or undersized pit. | Repair. |
| Loud grinding or rattling | Worn bearings or debris. | Usually replace. |
| Burning smell or tripped breaker | Motor failure. | Replace. |
When repair beats replacement
A stuck float, a failed check valve or a clogged intake are inexpensive fixes. A pump that is a few years old with a new float switch can run for years. Replace the pump when the motor is failing, the housing is cracked or repairs are repeating.
A pump has a limited life, and the cost of a failure during a storm is higher than the cost of replacing one early. Many homeowners replace pumps on a schedule. Our sump pump page explains the options, including battery backup.
A spring test routine
Once a year, before the wet season, pour a few buckets of water into the pit. The float should lift, the pump should start and the water should drop quickly and discharge outside. Listen for grinding and watch that the discharge does not leak at the joints.
Clean the intake screen, check the cord for damage and make sure the outlet is protected by a GFCI. If you have a battery backup, test it by unplugging the main pump while it is running and confirm the backup takes over.
A pump that passes this test is more likely to work when a storm arrives. If it does not, replace or repair it before the rain, not during it.
Pump failed in a storm?
Call the 24/7 line. We will walk through the checks and send a technician.
Where sump water can go in Vernon Hills
Lake County Public Works, which maintains the sanitary sewer here, has a sewer use ordinance that bars sump pumps, downspouts, footing drains and window well drains from the sanitary sewer. Discharge goes outside, away from the foundation.
Flooding is a real risk in this area. In July 2017, about six inches of rain fell in seven hours around Mundelein, and local news later reported a stormwater plan of roughly $10 million. A working pump with a backup is part of protecting a basement.
Source type: Lake County Public Works sewer use ordinance and local news reportBattery backups and maintenance
A battery backup keeps the pit empty when the power fails, which often happens in the same storms that raise the water. Test it a few times a year and replace the battery on schedule.
Each spring, pour water into the pit to test the pump, clean the pit and check the discharge outlet. If the basement still takes on water in storms, the problem may be bigger than the pump. See our basement waterproofing page.
Safety around a sump pit
Never reach into a pit with the pump plugged in. Unplug the pump first, and keep the cord out of any standing water. If the basement is already flooded, do not enter if water could be touching outlets or the panel.
A pump failure during a storm is stressful, but rushing creates risk. Call, describe what you see and let us help you decide what to do before anyone steps into water.
Choosing a new pump
Pump size depends on how fast water enters the pit and how high it must be lifted. A plumber can size it. Cast iron housings dissipate heat well, and thermoplastic housings resist corrosion.
Replace the check valve at the same time, because a worn one lets water drain back and makes the pump cycle. Our Mundelein page covers service in that area, where the 2017 flood left a strong memory.
Rules and guidance note
Follow the pump maker's guidelines. Pump repair is plumbing and electrical work, so keep power off while you work. The discharge must be routed with care, and the Village of Vernon Hills building department at 847-367-3700 can tell you what applies on your lot.
Illinois plumbers are licensed through IDPH, which offers a license lookup, so you can check anyone you hire.
Sump pump repair questions
Check power, the GFCI, the breaker and the float. A stuck float is the most common cause.
Several years, depending on use. Heavy use shortens its life.
Not under the Lake County Public Works ordinance. Discharge goes outside.
Yes. It keeps pumped water from flowing back into the pit.
Move belongings off the floor, stay out if water nears the panel and call a plumber.