Types of Sump Pumps: Pedestal vs. Submersible
The two main residential sump-pump designs are submersible and pedestal.
Both remove groundwater from a sump basin. The main difference is where the motor and pumping assembly sit:
- Submersible sump pump: the pump and motor operate down inside the sump basin.
- Pedestal sump pump: the pumping components extend into the basin while the motor remains above the pit.
Neither design is automatically better for every basement. The correct choice depends on the basin, required flow at the actual operating head, float clearance, noise, service access, backup strategy, and how much groundwater the system has to handle.
For a new Chicago system, start with the complete installation rather than choosing a pump by type or horsepower alone. See Sump Pump Installation.
Pedestal vs. Submersible: Quick Comparison
| Feature | Submersible sump pump | Pedestal sump pump |
|---|---|---|
| Motor location | Inside the basin | Above the basin |
| Typical noise | Usually quieter | Usually more audible |
| Service access | Pump is accessed inside the basin | Motor and switch are easier to reach |
| Basin space | Pump body and float need room inside the pit | Motor stays above the pit, but column, intake and float still need clearance |
| Motor cooling | Designed for submerged operation; many models use oil-filled or water-surrounded heat dissipation | Motor is air-cooled above the basin |
| Covered-basin layout | Common in modern packaged sump systems | Cover must accommodate the pedestal column and above-pit motor |
| Best use | Where its pump curve, basin fit, noise and backup layout match the system | Where its pump curve, basin geometry and above-pit access fit the system |
Zoeller’s current selection guidance describes submersible pumps as quieter and less prone to overheating, while pedestal pumps are easier to access and repair. Those are useful design differences, not a universal ranking.
Zoeller: choosing a sump-pump type →
What Is a Submersible Sump Pump?
A submersible sump pump is designed to operate with the pump down in the basin. The motor is sealed for that environment.
Current residential examples include Zoeller’s Model 53 and Model 98 and Liberty’s 230-, 250-, 280-, 290- and 450-Series sump pumps.
- Pump body sits inside the basin
- Can use an integral or separate float/control
- Connects to vertical discharge piping
- Works with a sump-pump check valve
- Can share a properly sized basin with compatible backup equipment
Zoeller Model 53 example →
Liberty residential sump-pump lineup →
What Is a Pedestal Sump Pump?
A pedestal pump uses a vertical assembly with the motor mounted above the sump pit while the lower pumping components extend into the water.
Zoeller currently sells multiple pedestal basement sump models, including the Model 81 and Model 82 at 1/3 HP and Model 84 at 1/2 HP.
The above-pit motor is air-cooled and easier to reach for inspection or service than a motor sitting down in the basin.
Zoeller Model 81 pedestal example →
Why Are Submersible Pumps Usually Quieter?
The motor and pump sit below floor level inside the sump basin rather than above the room.
That layout generally reduces how much motor sound reaches the basement. A cover can reduce perceived noise further.
Noise still depends on the entire installation:
- Check-valve closure and water hammer
- Pipe support
- Vibration
- Pump model
- Basin cover
- Discharge velocity
A quiet pump attached to a poorly supported discharge line can still produce a noisy system.
Why Are Pedestal Pumps Easier to Access?
The pedestal motor and much of the switch mechanism sit above the basin, so those components do not require reaching down into the pit for basic access.
That can be useful where service access is a priority.
Easy access does not make a pedestal pump automatically better. It still needs to provide the required flow at the home’s actual operating head and fit the basin without float interference.
Which Type Pumps More Water?
You cannot determine flow capacity from “submersible” or “pedestal” alone.
Compare the performance curve of the exact pump model at the system’s total dynamic head.
- Required gallons per minute
- Vertical lift
- Pipe length and diameter
- Elbows and fittings
- Check-valve resistance
- Peak incoming groundwater
For example, Zoeller currently offers both a 1/2 HP Model 98 submersible designed for high-flow basement sump applications and a 1/2 HP Model 84 pedestal. The horsepower label alone does not tell you which model fits a particular system.
Zoeller Model 98 submersible example →
Zoeller Model 84 pedestal example →
Chicago Basin Size Matters Before Pump Type
Chicago’s current general sump-pit provision says a sump pit must generally be at least 18 inches in diameter and 30 inches deep unless otherwise approved. The pit needs a removable cover adequate for anticipated loads, and the floor or cover must provide permanent support for the pump.
Chicago Plumbing Code 18-29-1111.3.2 →
Those minimum dimensions do not automatically guarantee ideal space for every pump/float/backup combination.
The usable layout still needs enough room for:
- Primary pump
- Primary float or level control
- Discharge piping
- Check valve
- Backup pump if installed
- Backup float/control
- Service access
Which Type Is Better for a Small Sump Basin?
It depends on the exact basin and control geometry.
A pedestal pump keeps the motor out of the pit, but the pumping column and float mechanism still need room.
A compact submersible can also fit a smaller layout, particularly with a compact vertical control, but the pump body and float must have unobstructed clearance.
A crowded basin can cause:
- Float interference
- Failure to start
- Failure to shut off
- Short-cycling
- Primary and backup controls interfering with each other
Which Type Is Better for a Finished Basement?
Finished basements often place more value on quiet operation, a covered pit, alarm/backup protection, and a clean installation. Those preferences can make a submersible system attractive.
But the consequence of failure matters more than the mechanical layout alone. A finished basement should also be evaluated for:
- Primary-pump capacity
- Independent backup protection
- High-water alarm
- Discharge capacity
- Check-valve function
- Testing and maintenance access
Battery Backup Sump Pump Installation →
Which Type Is Easier to Maintain?
Pedestal pumps generally make the motor and switch easier to access because they remain above the basin.
Submersible pumps usually require access inside the sump pit for major service or replacement.
Installation details can narrow that difference. A submersible system with a removable cover, accessible union/coupling, properly positioned check valve, and clear piping can still be straightforward to remove and service.
Which Type Lasts Longer?
There is no reliable universal lifespan winner between pedestal and submersible pumps.
Zoeller describes pedestal pumps as capable of long service life and highlights reduced overheating risk as a submersible advantage. Actual service life still depends on:
- Number of cycles
- Run time
- Correct sizing
- Switch reliability
- Debris and sediment
- Discharge restrictions
- Check-valve performance
- Maintenance
Do not select a pump type from a claimed lifespan number alone.
Which Type Is More Energy Efficient?
Do not compare efficiency from pedestal versus submersible alone.
Energy use depends on motor design, pump efficiency, total dynamic head, delivered flow, cycling frequency, and whether the system is wasting work by pumping water that falls back or returns to the foundation.
The best comparison is the exact model’s operating performance for the actual application.
Does a Submersible Pump Need to Stay Underwater?
A submersible sump pump is designed to operate in the basin, but the exact minimum operating level and cooling requirements depend on the model.
Do not apply a generic “must always be completely submerged” rule. Follow the installation and operating instructions for the exact pump.
For example, current Zoeller submersible models use sealed, oil-filled motor designs for heat dissipation, while other manufacturers use different construction.
Can a Pedestal Motor Get Wet?
The lower pumping components operate in sump water, but the pedestal motor is designed to remain above the pit.
Zoeller’s current Model 81, 82 and 84 documentation specifically describes the motor as mounted above the pit cover and air-cooled.
If a basement water event can reach the pedestal motor, the system has progressed beyond normal sump operation and needs urgent flood-control attention.
Primary Pump Type vs. Backup Pump Type
“Pedestal vs. submersible” describes the mechanical layout of the primary pump. Backup systems are another layer of classification.
| Category | Purpose |
|---|---|
| Primary submersible pump | Normal groundwater pumping from inside the basin |
| Primary pedestal pump | Normal groundwater pumping with motor above the basin |
| Battery backup pump | Secondary pumping during primary failure, outage, or high-water condition depending on system |
| Water-powered backup | Secondary pumping using municipal water pressure |
| Primary + backup combo system | Preconfigured or coordinated primary and backup pumps |
Liberty currently sells assembled primary-plus-battery-backup combinations, illustrating that “pump type” can refer either to mechanical layout or to the role the pump plays in the protection system.
Liberty primary + battery-backup combo example →
Are Effluent, Drain and Sewage Pumps Types of Sump Pumps?
Not in the simple residential “pedestal vs. submersible sump pump” sense.
Some manufacturers sell pump models approved for more than one application—for example, sump/effluent models—but a drain pump or sewage pump serves a different drainage job.
- Sump pump: groundwater or drainage collected in a sump basin
- Drain pump: gray-water drainage from fixtures/applications that need pumping
- Sewage pump/ejector: sanitary wastewater that may contain solids
- Grinder pump: sewage pumping where solids are ground before discharge
Do not substitute one pump category for another because the horsepower or discharge size looks similar.
Crawl-Space Sump Pumps
A crawl-space sump pump is usually not a separate motor technology. It is a sump system configured for the space, access, basin, drainage load, and discharge conditions of a crawlspace.
Manufacturers currently sell packaged crawl-space sump systems using compact submersible pumps.
Crawl Space Sump Pump Installation →
Can You Add Battery Backup to Either Primary Type?
Potentially, yes, but the basin and system have to support the additional equipment.
- Enough physical room for the backup pump
- Independent float/control clearance
- Correct activation levels
- Adequate discharge capacity
- Correct check-valve arrangement
- Battery/controller installation that follows manufacturer requirements
The backup layout should be evaluated separately from the pedestal-versus-submersible decision.
Which Sump Pump Type Fits a Chicago Basement?
A submersible design may fit well when:
- Quieter operation matters
- The basin provides enough room for the pump and float
- A covered basin is preferred
- The selected submersible’s performance curve matches the required flow/head
- Backup equipment can fit without control interference
A pedestal design may fit well when:
- Above-pit motor/switch access is valuable
- The basin geometry suits the pedestal column and float
- The selected pedestal’s performance curve matches the required flow/head
- The above-pit motor location works with the basin cover and basement layout
These are fit considerations, not a ranking. The correct pump is the one designed for the application and capable of handling the actual water load.
What to Compare Before Replacing the Existing Pump
- Existing pump make and model
- Pedestal or submersible layout
- Performance at actual operating head
- Whether the old pump kept up during the worst known water events
- Basin diameter and depth
- Usable float range
- Discharge-pipe size and route
- Check-valve condition
- Backup-pump space
- Noise requirements
- Service access
If the old system performed well, preserve the useful hydraulic characteristics unless there is a specific reason to change them.
If it struggled, changing from pedestal to submersible—or the reverse—will not necessarily solve the real problem. The issue may be pump capacity, discharge head, check-valve backflow, basin volume, or groundwater inflow.
Types of Sump Pumps FAQ
What are the two main types of sump pumps?
The two main residential mechanical designs are submersible and pedestal. A submersible pump operates down in the basin, while a pedestal pump keeps its motor above the pit.
Which is better: pedestal or submersible sump pump?
Neither is universally better. Submersibles are generally quieter, while pedestal motors are easier to access. The correct choice depends on the basin, pump curve, water load, float clearance, noise, backup layout, and service needs.
Are submersible sump pumps quieter?
Usually. The motor operates below floor level inside the basin, and current Zoeller selection guidance specifically identifies quiet operation as an advantage of submersible pumps.
Are pedestal sump pumps easier to repair?
They are generally easier to access because the motor and switch are above the basin. Whether a specific repair is practical still depends on the model and failed component.
Do pedestal sump pumps last longer?
There is no universal lifespan advantage. Pedestal pumps can have long service lives, but cycling, sizing, pump quality, switch condition, discharge design, and maintenance all affect longevity.
Can I replace a pedestal pump with a submersible pump?
Often, if the basin has enough room and the new pump provides the required flow at the actual head. Float clearance, discharge piping, check valve, cover, and backup layout also need to fit.
Can I replace a submersible pump with a pedestal pump?
Sometimes. The basin, cover, float geometry, required flow/head, and above-pit motor location all need to suit the pedestal design.
Choose the Type After You Understand the System
Pedestal and submersible pumps solve the same groundwater problem with different layouts. Choose between them after checking basin dimensions, required pumping capacity, float clearance, discharge conditions, noise, service access, and backup strategy.
Sump Pump Installation →
Sump Pump Replacement →
Sump Pump Maintenance →