Ejector Pump Repair in Chicago
A sewage ejector pump handles wastewater from plumbing fixtures that cannot drain to the building sewer by gravity. If a basement toilet, shower, sink, laundry connection, or other below-sewer fixture backs up, the problem may be in the ejector system rather than the groundwater sump pump.
Ejector-pump diagnosis should separate the pump itself from the float/control, check valve, discharge piping, basin cover, vent, power supply, and downstream sewer. Replacing the pump without identifying the failed part can leave the original problem in place.
If wastewater is rising or fixtures connected to the ejector system are backing up, stop using those affected fixtures until the system is diagnosed.
Sump Pump vs. Sewage Ejector Pump
| System | What it handles | Typical source |
|---|---|---|
| Groundwater sump pump | Groundwater and drainage water | Drain tile / sump basin |
| Sewage ejector pump | Sanitary wastewater and sewage | Below-sewer plumbing fixtures |
Chicago’s current plumbing code defines this distinction by function: building drains that cannot discharge to the sewer by gravity must discharge into a tightly covered and vented sump and then be lifted into the building gravity drainage system by automatic pumping equipment or another approved method.
Chicago Plumbing Code 18-29-712.1 →
If the problem is clear groundwater rising in a sump basin rather than sanitary wastewater, use Sump Pump Repair.
Signs an Ejector Pump System Needs Diagnosis
- Basement toilet, shower, sink, or laundry fixture backs up
- High-water or ejector alarm activates
- Pump does not start as the basin fills
- Pump runs but the wastewater level does not fall
- Pump runs continuously
- Pump starts and stops too frequently
- Wastewater returns after the pump shuts off
- Breaker or protective device trips when the pump starts
- Unusual humming, rattling, or grinding
- Sewage odor around the ejector basin
- Leakage around the basin cover or piping penetrations
Those symptoms do not all mean the pump motor is bad. Float interference, check-valve backflow, a discharge restriction, a downstream sewer problem, venting, or a basin-seal problem can create similar complaints.
Chicago Ejector-Pump Requirements That Matter During Repair
Automatic Pumping
Chicago’s current code says a sewage pump or sewage ejector must automatically discharge the contents of the sump into the building drainage system.
Chicago Plumbing Code 18-29-712.4 →
Check Valve and Gate Valve
Chicago currently requires a check valve in the pump/ejector discharge arrangement and an accessible gate valve on the discharge side of that check valve before the gravity drainage system.
The current section was amended June 17, 2026 and also specifies valve-access requirements.
Chicago Plumbing Code 18-29-712.2 →
Capacity and Solids Handling
The pump must have the capacity and head required for the application. If the ejector receives discharge from water closets, Chicago’s current code requires a sewage pump/ejector capable of handling spherical solids up to and including 2 inches, with a separate exception for qualifying grinder pumps/ejectors.
Chicago Plumbing Code 18-29-712.4.1 →
Venting
Below-sewer drainage and sewage-ejector sumps require proper venting. Chicago’s current vent provisions size sewage-pump/ejector sump vents according to pump discharge capacity and developed vent length.
Chicago Plumbing Code 18-29-916.5.1 →
Common Ejector Pump Failure Modes
Float or Level-Control Problem
The control has to start the pump when the wastewater level reaches the ON point and shut it off after the basin is lowered.
- Float obstructed by the basin wall or piping
- Float unable to reach the OFF position
- Incorrect control positioning
- Failed float or switch
- Control-panel problem on systems that use a panel
Do not reach into an energized sanitary basin or bypass the control as a homeowner troubleshooting method.
Check-Valve Backflow
A leaking, stuck-open, missing, or improperly functioning check valve can allow discharged wastewater to return toward the basin.
That can produce repeated cycling even when the pump itself is capable of moving the wastewater.
Discharge Restriction
A pump cannot deliver its rated performance when the discharge path is obstructed or when the actual head exceeds what the selected pump can handle.
- Blocked or restricted piping
- Valve problem
- Foreign material in the pump or line
- Downstream drainage or sewer restriction
- Pump selected for less head than the system actually imposes
Pump or Motor Failure
A failed pump may remain silent, hum without useful pumping, trip electrical protection, or move substantially less wastewater than expected.
Do not diagnose a motor failure from sound alone. A blocked pump, air-related issue, control problem, discharge restriction, or electrical problem can produce similar symptoms.
Basin Cover, Seal, or Vent Problem
An ejector basin is part of the sanitary drainage system, not an open groundwater pit.
Sewage odor, leakage around the lid, or unusual pressure behavior can point toward the cover, gasket, piping penetrations, or venting rather than the pump motor.
Residential Sewage Pumps Are Designed for Different Material Than Sump Pumps
Current residential sewage-pump products illustrate why a groundwater sump pump should not simply be substituted into an ejector application.
Liberty’s current residential sewage-system information describes sewage pumps as moving liquids and soft solids from a sewage basin to a sewer or septic system. Its LE50 residential/light-commercial sewage pump uses a 2-inch discharge and is rated for 2-inch solids handling.
Liberty Pumps sewage systems →
Liberty LE50 sewage-pump example →
Zoeller’s current Model M267 is likewise designed for residential sewage-ejector applications, uses automatic float operation, and is rated to pass 2-inch spherical solids.
Zoeller M267 sewage-pump example →
Those are product examples, not universal model recommendations. The correct pump has to match the application’s flow, head, solids-handling requirement, basin, controls, voltage, and current code requirements.
Pump Runs but the Basin Does Not Empty
If the motor runs but the wastewater level remains high, possible directions include:
- Pump or impeller obstruction
- Discharge-line obstruction
- Valve not opening correctly
- Air-related pumping problem
- Excessive system head
- Pump damage or lost performance
- Downstream sewer restriction
Continued fixture use can add more wastewater while the system is unable to discharge, so stop using the affected fixtures when the basin level is rising.
Pump Will Not Shut Off
Continuous operation does not automatically mean the pump is undersized.
- Float/control cannot reach the OFF position
- Control or panel failure
- Wastewater returning through the discharge
- Check-valve failure
- Ongoing inflow greater than normal
Leaving a sewage pump running continuously without diagnosing the cause can increase wear and does not resolve the underlying sanitary-system problem.
Ejector Pump Short-Cycling
Frequent starts can be caused by control settings, limited usable basin volume, or wastewater returning after shutdown.
A larger pump is not automatically the fix. The float range, basin, check valve, discharge system, and actual inflow should be checked before changing pump capacity.
Sewage Odor Around the Ejector Basin
Sewage odor deserves system-level diagnosis.
- Cover or gasket not sealing correctly
- Loose or failed pipe penetration
- Vent problem
- Leakage around the sanitary basin
- Another nearby plumbing trap or sewer issue
Do not treat a sewage ejector basin like an open sump pit. Chicago’s below-sewer drainage provision requires a tightly covered and vented sump.
Ejector Pump Problem vs. Main Sewer Problem
| Symptom | More likely direction |
|---|---|
| Only below-grade fixtures feeding ejector basin back up | Ejector pump/control/discharge deserves diagnosis |
| Ejector basin high and pump silent | Power, float/control, or pump |
| Pump runs but basin remains high | Pump, obstruction, valve, discharge, or excessive head |
| Wastewater falls back after shutdown | Check valve / discharge |
| Multiple fixtures throughout building back up | Downstream building sewer / public sewer issue may be involved |
| Clear groundwater rising in separate sump basin | Groundwater sump system |
Sewer Backup Prevention →
Overhead Sewer Systems →
Repair vs. Replace
| Condition | Likely direction |
|---|---|
| Float/control obstruction or serviceable switch fault | Component repair may be practical |
| Failed check valve | Valve repair/replacement |
| Leak or serviceable piping problem | Repair if rest of system is sound |
| Pump or motor has failed | Pump replacement becomes more relevant |
| Repeated failures plus poor pump condition | Replacement/system correction may be more practical |
| Wrong pump for required head/solids/application | Correct pump/system design |
| Downstream sewer restriction | Correct sewer-side problem rather than replacing a healthy ejector pump |
Age alone should not decide the repair. The pump’s actual condition, output, control system, basin, discharge, and history of repeated problems matter together.
What to Do if Wastewater Is Rising
- Stop using fixtures that discharge into the affected ejector basin
- Keep children and pets away from wastewater
- Avoid direct contact with sewage or sewage-contaminated water
- Do not open or reach into an energized sanitary basin
- Do not operate electrical equipment while standing in water
- Arrange diagnosis before the basin overflows
Current CDC guidance says floodwater and standing water can contain sewage and other hazards. If electrical circuits or equipment are wet or near standing water, do not enter the water to reach a switch and do not operate electrical equipment while standing in water.
What an Ejector Pump Diagnosis Should Establish
- Which fixtures actually discharge into the ejector basin
- Whether the basin level is high
- Whether the pump receives power and attempts to run
- Whether the float/control moves and switches correctly
- Whether the pump lowers the wastewater level under load
- Whether wastewater returns after shutdown
- Whether the check valve and required discharge valves function correctly
- Whether the discharge line is restricted
- Whether the basin cover and penetrations remain sanitary and sealed
- Whether the vent is functioning as designed
- Whether the selected pump meets the required head and application
- Whether a downstream sewer problem is contributing to the backup
The goal is to identify the failed component before recommending a new pump.
Ejector Pump Repair FAQ
Is an ejector pump the same as a sump pump?
No. A sump pump handles groundwater or drainage water. A sewage ejector pump handles sanitary wastewater from fixtures that cannot drain to the sewer by gravity.
Why is my ejector pump alarm going off?
A high-level alarm can indicate that the basin level is higher than expected. Possible causes include pump failure, power loss, a float/control problem, a discharge restriction, check-valve backflow, or unusually high inflow.
Why does my ejector pump keep running?
Possible causes include a float/control that cannot reach the OFF position, control-panel trouble, wastewater returning through a failed check valve, or continued inflow. Continuous running should be diagnosed rather than assumed to mean the pump is too small.
Why does the ejector basin smell like sewage?
Odor can indicate a cover or gasket problem, loose pipe penetration, venting problem, sanitary leakage, or another nearby plumbing issue. Chicago requires below-sewer drainage sumps to be tightly covered and vented.
Does Chicago require a check valve on an ejector pump?
Chicago’s current plumbing code requires a check valve in the pump/ejector discharge arrangement and an accessible gate valve on the discharge side of the check valve before the gravity drainage system.
Can I keep using the basement toilet if the ejector pump stops?
If that toilet discharges into the ejector basin, continued use adds wastewater while the system may be unable to pump it away. Stop using affected fixtures when the basin is high or wastewater is backing up.
Do I automatically need a new ejector pump if fixtures back up?
No. A backup can be caused by the float/control, check valve, discharge piping, basin/vent system, pump, or a downstream sewer restriction. Diagnose the system before replacing the pump.
Request Ejector Pump Diagnosis in Chicago
When requesting service, note which fixtures are affected, whether an alarm is active, whether the pump is silent or running, whether the basin level is rising, and whether wastewater returns after the pump stops.