Submersible vs Jet Pump

Understanding Well Pump Types

When it comes to pumping water from your well, you have two primary options: submersible pumps and jet pumps. Each technology has evolved over decades to serve specific needs, and understanding their fundamental differences is crucial for making the right choice.

The well pump you choose affects everything from your initial investment to long-term operating costs, water pressure consistency, maintenance requirements, and overall system reliability. Making the wrong choice can result in premature pump failure, inadequate water pressure, excessive energy bills, or the need for costly replacement before the pump's expected lifespan.

In Southern California, where well depths can vary dramatically from 50 feet in coastal areas to 400+ feet in mountain communities, pump selection becomes even more critical. The unique geological conditions across San Diego, Riverside, and San Bernardino counties mean there's no one-size-fits-all answer.

How Submersible Pumps Work

Submersible pumps are engineering marvels designed to operate completely underwater, deep inside your well. The entire pump assembly—motor, impellers, and all—sits submerged beneath the water level, typically positioned 10-20 feet above the bottom of the well.

Key Components

• Watertight Motor: A specially sealed electric motor designed to operate while submerged, cooled by the surrounding water
• Impeller Stack: Multiple impellers (rotating blades) stacked in series, each adding pressure to push water upward
• Drop Pipe: The pipe that carries water from the pump to the surface
• Safety Rope: A backup support system in case of pipe failure
• Electrical Cable: Special waterproof wiring running from the pump to the control box above ground

Operating Principle

Unlike jet pumps that pull water up through suction, submersible pumps push water up from below. This pushing action is inherently more efficient because it works with gravity rather than against it. Water enters through an intake screen, passes through the impeller stack where each impeller adds pressure, and is forced up through the drop pipe to your pressure tank.

The motor generates minimal heat because it's continuously cooled by the surrounding water. This cooling effect is one reason submersible pumps tend to last longer than their above-ground counterparts—the motor never overheats, even during extended operation.

How Jet Pumps Work

Jet pumps, also called ejector pumps, operate from above ground using a fascinating combination of pressure and suction. Rather than submerging the pump in the well, jet pump systems use the venturi effect to create suction that draws water up from below.

Two Types of Jet Pumps

Shallow Well Jet Pumps (Single-Line)

For wells up to 25 feet deep, a single-line jet pump uses one pipe that extends into the well. The pump creates suction that draws water up through this single pipe. The ejector (jet) is built into the pump housing above ground.

Deep Well Jet Pumps (Dual-Line)

For deeper wells (25-100+ feet), dual-line systems use two pipes. One pipe delivers pressurized water down to an ejector (jet) assembly located inside the well, near the water level. This ejector creates the venturi effect that boosts suction, and a second pipe carries the water-plus-boost mixture back up to the pump.

Key Components

• Impeller Pump: Creates the pressure that powers the system
• Ejector (Jet) Assembly: Creates the venturi effect for boosted suction
• Foot Valve: A check valve at the bottom of the suction pipe to maintain prime
• Pressure Tank: Stores pressurized water and reduces pump cycling
• Priming Chamber: Holds water needed to start the suction process

The Priming Requirement

Unlike submersible pumps, jet pumps must be "primed" with water before they can operate. If the system loses prime (the water in the suction line drains away), the pump cannot create suction and will run without pumping water. This is a key maintenance consideration that submersible pumps avoid entirely.

Complete Comparison Table

Depth Considerations: The Critical Factor

Well depth is often the single most important factor in choosing between submersible and jet pumps. Physics imposes fundamental limits on how far you can pull water up using suction, which is the principle jet pumps rely on.

The Physics of Suction

At sea level, atmospheric pressure is approximately 14.7 PSI. This pressure is what allows suction to work—when you create a vacuum, atmospheric pressure pushes water up into it. However, atmospheric pressure can only support a water column of about 34 feet under perfect conditions. In practice, with friction losses, imperfect seals, and other real-world factors, jet pumps can only reliably lift water about 25 feet.

Shallow Wells (Under 25 Feet)

For shallow wells with static water levels less than 25 feet below ground, both pump types can work effectively. Jet pumps are often chosen here because:

• Lower initial cost
• Easy installation and maintenance
• Adequate efficiency for shallow applications
• Simple DIY replacement if needed

Medium Depth Wells (25-100 Feet)

In this range, you have options. Deep-well jet pumps with dual-line systems can work, but submersible pumps often make more sense:

• Better efficiency saves money over time
• More consistent water pressure
• No priming issues during power outages
• Longer lifespan offsets higher initial cost

Deep Wells (Over 100 Feet)

For wells deeper than 100 feet, submersible pumps are the only practical choice. In Southern California communities like Julian, Borrego Springs, and the High Desert areas of San Bernardino County, wells commonly reach 200-400+ feet. Submersible technology makes these depths accessible and affordable.

Efficiency and Energy Costs

Over the lifetime of your pump, energy costs can exceed the initial purchase price several times over. Understanding efficiency differences is crucial for long-term cost analysis.

Why Submersible Pumps Are More Efficient

Submersible pumps achieve 50-70% efficiency for several reasons:

• Pushing vs. Pulling: Pushing water up is inherently more efficient than trying to pull it with suction
• No Priming Energy Waste: Jet pumps waste energy maintaining the ejector circulation loop
• Better Motor Cooling: Water cooling allows motors to run at optimal efficiency
• Direct Drive: Power goes directly into pumping, not into creating suction

Energy Cost Comparison

Consider a typical household using 150 gallons of water per day from a 200-foot well:

*Based on California average electricity rate of $0.20/kWh

Over 15-20 years, the submersible pump's energy savings often exceed $1,000-$2,000, which can offset much of the higher initial installation cost.

Cost Comparison: Short-Term vs. Long-Term

Initial Costs

Jet pumps win on upfront costs:

Total Cost of Ownership (20 Years)

When you factor in lifespan, efficiency, and maintenance, the picture changes:

Despite higher upfront costs, submersible pumps often cost less over their lifetime—while also providing better performance, reliability, and water pressure.

Maintenance Requirements

Jet Pump Maintenance

Jet pumps require more regular attention:

• Prime Checking: Verify system is primed, especially after power outages
• Foot Valve Inspection: Annual check for leaks that cause loss of prime
• Motor Lubrication: Some models require periodic bearing lubrication
• Ejector Cleaning: Deep-well jets may need occasional cleaning
• Freeze Protection: Annual winterization in cold-prone areas
• Belt Inspection: If belt-driven, check for wear annually

Submersible Pump Maintenance

Submersible pumps require minimal maintenance:

• Annual Inspection: Check amp draw and pressure readings
• Control Box Check: Verify capacitor and relay function
• Pressure Tank Service: Check air charge annually
• Wire Connections: Inspect above-ground connections

The tradeoff: when submersible pumps do need service, the pump must be pulled from the well—a job requiring specialized equipment and expertise. Jet pump repairs are usually simpler and can often be DIY.

Pros and Cons Summary

Submersible Pump Pros

• Works at any well depth
• Highest efficiency (50-70%)
• Longer lifespan (15-25 years)
• Silent operation
• No priming required—always ready
• Protected from weather and freezing
• Higher flow rates possible
• Lower lifetime cost

Submersible Pump Cons

• Higher initial cost
• Professional installation required
• Expensive to repair or replace
• Requires pulling from well for any service
• Motor damage if run dry

Jet Pump Pros

• Lower upfront cost
• Easy above-ground access for repairs
• DIY-friendly installation and maintenance
• Simple technology, easy to understand
• Quick troubleshooting

Jet Pump Cons

• Limited to shallow/medium wells
• Lower efficiency (25-50%)
• Shorter lifespan (10-15 years)
• Audible noise during operation
• Requires priming and can lose prime
• Needs freeze protection
• Higher operating costs over time

Which Pump Is Best for You?

Choose a Submersible Pump If:

• Your well is deeper than 25 feet (especially over 100 feet)
• You want the most reliable, longest-lasting option
• Energy efficiency and low operating costs matter
• You prefer quiet operation
• You don't want to worry about priming or freezing
• You need high flow rates or consistent pressure
• You're building new or doing a complete pump replacement

Choose a Jet Pump If:

• Your well is shallow (under 25 feet)
• Budget constraints require lowest upfront cost
• You want easy DIY access for repairs
• You're replacing an existing jet pump and the well is shallow
• The well casing is too narrow for a submersible (under 4")

Our Recommendation for Southern California

For most Southern California homeowners with wells deeper than 50 feet, we recommend submersible pumps. The combination of efficiency, reliability, and longevity makes them the superior long-term investment. While the initial cost is higher, the lower operating costs and extended lifespan typically result in lower total cost of ownership.

For genuinely shallow wells under 25 feet, jet pumps remain a cost-effective option, especially if budget is the primary concern.

Frequently Asked Questions