💧 Little Giant 3E-34N Submersible Pump – 1/15 HP, 670 GPH Oil-Filled Dual Purpose

Versatile, compact submersible pump for water features, pool draining, and industrial liquid transfer

♨️ Product Overview

The Little Giant 3E-34N (Part No. 503603) is a 1/15 HP oil-filled dual-purpose submersible pump manufactured by Little Giant, a division of Franklin Electric — one of America’s most trusted names in pump technology for over 80 years. This compact yet powerful pump delivers up to 670 gallons per hour at 1 foot of lift with a maximum shut-off head of 20.3 feet (8.8 PSI).

Designed for true dual-purpose versatility, the 3E-34N can operate fully submerged or in-line (fed with pipe or hose), making it ideal for a wide range of applications including spa and hot tub draining, pool cover water removal, statuary fountains, water displays, air conditioning systems, and machine tool coolant recirculation. The oil-filled motor provides superior thermal protection and continuous bearing lubrication for extended service life, while the epoxy-coated die-cast aluminum housing and stainless steel backplate deliver corrosion-resistant durability. A fluoroelastomer (FKM/Viton) shaft seal and polypropylene debris screen protect internal components in demanding environments. The 3E-34N includes a 10-foot power cord and handles liquid temperatures up to 120°F (49°C).

✨ Key Features

✅ 1/15 HP Oil-Filled Motor – Dielectric oil filling provides thermal protection and continuous bearing lubrication for extended pump life

✅ 670 GPH Flow Rate – Delivers up to 670 gallons per hour at 1 foot of lift (11.1 GPM) for efficient water movement

✅ Dual-Purpose Operation – Can be used fully submerged or mounted in-line, fed with pipe or hose for maximum versatility

✅ 20.3 Ft Maximum Shut-Off Head – 8.8 PSI capability handles significant elevation changes for varied installations

✅ Epoxy-Coated Die-Cast Aluminum Housing – Corrosion-resistant construction for durability in wet environments

✅ Stainless Steel Backplate – Provides additional structural integrity and corrosion resistance

✅ Fluoroelastomer (FKM/Viton) Shaft Seal – Chemical-resistant seal handles a wide range of liquid types

✅ Polypropylene Debris Screen – Protects the nylon impeller from debris damage in submersible applications

✅ 120°F Maximum Liquid Temperature – Suitable for hot tub and spa draining, heated water features, and warm industrial liquids

✅ 10-Foot Power Cord – Generous cord length simplifies installation and provides flexible positioning options

✅ Thermal Overload Protection – Built-in motor protection prevents overheating damage

✅ UL Listed – Independently tested and certified for safety compliance

⚙️ Technical Specifications

Specification	Value
Manufacturer	Little Giant (Franklin Electric)
Model	3E-34N
Part Number	503603
UPC	010121036031
Pump Type	Submersible / In-Line (Dual Purpose)
Motor Type	Oil-Filled, Direct Drive
Horsepower	1/15 HP
Voltage	115V
Frequency	60 Hz
Phase	Single
Amperage	2.5 A (manufacturer spec)
Wattage	200W
Flow Rate (at 1 ft)	670 GPH (11.1 GPM)
Flow Rate (at 3 ft)	650 GPH
Flow Rate (at 5 ft)	575 GPH
Flow Rate (at 10 ft)	460 GPH
Maximum Flow Rate	11 GPM
Shut-Off Head	20.3 ft (8.8 PSI)
Maximum Liquid Temperature	120°F (49°C)
Discharge Port	1/2″ MNPT
Intake Port	3/4″ MNPT
Impeller Material	Nylon
Housing Material	Epoxy-Coated Die-Cast Aluminum
Volute Material	Nylon
Backplate Material	Stainless Steel
Shaft Seal	Fluoroelastomer (FKM/Viton)
Screen Material	Polypropylene
Cord Length	10 ft
Dimensions (L × W × H)	5.5″ × 7″ × 8.25″
Motor Protection	Thermal Overload
Certification	UL Listed
Speed	Single Speed

🔌 Electrical Requirements

Electrical Spec	Requirement
Supply Voltage	115V
Frequency	60 Hz
Phase	Single
Amperage	2.5 A (manufacturer spec)
Wattage	200W
Cord Length	10 ft
Cord Type	3-prong grounded plug

⚠️ IMPORTANT:

All electrical connections must comply with the National Electrical Code (NEC) and all applicable local codes and regulations.

The pump must be connected to a properly grounded electrical outlet. Do not use an extension cord.

GFCI (Ground Fault Circuit Interrupter) protection is required for all pool, spa, and outdoor water feature installations per NEC requirements.

Do not operate the pump in areas where flammable liquids or gases are present.

Ensure the power supply voltage matches the pump’s nameplate voltage (115V) before connecting.

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📊 Performance Curve Data

Lift Height	Flow Rate (GPH)	Flow Rate (LPH)
1 ft	670	2,536
3 ft	650	2,461
5 ft	575	2,177
10 ft	460	1,741
20.3 ft (shut-off)	0	0

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🔗 Compatibility Guide

This Pump:

📍 Discharge: 1/2″ MNPT 📍 Intake: 3/4″ MNPT 📍 Voltage: 115V / 60Hz only 📍 Operation: Submersible or In-Line

Connection Options:

The 3E-34N uses standard MNPT (Male National Pipe Thread) connections, compatible with standard NPT plumbing fittings, brass adapters, PVC fittings, and flexible vinyl tubing with appropriate hose barb adapters.

Replacement Parts:

Part	Description
Volute	Little Giant volute for 3E-34N (Nylon, Black, 3/4″ FPT × 1/2″ MPT)
Volute Gasket	Volute gasket for Little Giant 3E/4E/3-ABS series
Shaft Seal	FKM/Viton replacement shaft seal

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🛠️ Installation Requirements

Submersible Installation:

Requirement	Specification
Positioning	Any attitude; preferably with volute down or to the side
Submersion	Fully submerged in liquid
Minimum Water Depth	Can operate down to 1/8″ water depth
Weight Support	Must be adequately supported — do NOT support by discharge connection alone
Mounting	Two mounting holes in back of pump (accept #8 self-tapping screws, max hole depth 0.37″)

In-Line Installation:

Requirement	Specification
Intake Connection	3/4″ MNPT (pipe or hose fed)
Discharge Connection	1/2″ MNPT
Flow Restriction	To reduce flow, place valve on discharge side; or use a clamp on flexible tubing

Installation Notes:

⚠️ Do not restrict the intake side of the pump — this may cause seal damage and starve the pump. For reduced flow rates, restrict the discharge side only.

⚠️ Do not support the pump by the discharge connection alone. Use the two mounting holes on the back of the pump for secure installation.

⚠️ The oil-filled motor is factory-sealed and requires no lubrication. Do not attempt to add oil or open the motor housing.

⚠️ Maximum liquid temperature is 120°F (49°C). Do not pump liquids exceeding this temperature.

⚠️ Do not pump flammable, explosive, or corrosive liquids unless the pump is specifically rated for such use.

⚠️ Ensure GFCI protection is in place for all outdoor, pool, spa, and water feature installations.

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🔧 Maintenance Guide

Routine Maintenance:

Task	Frequency	Notes
Inspect debris screen	Monthly	Remove accumulated debris; clean with water
Check discharge connection	Monthly	Ensure fittings are tight and leak-free
Inspect power cord	Monthly	Check for damage, cuts, or exposed wiring
Verify GFCI function	Monthly	Test GFCI outlet or breaker per manufacturer instructions
Clean pump exterior	As needed	Wipe down housing; remove mineral buildup
Check flow rate	Periodically	Reduced flow may indicate screen blockage or worn impeller

Warning Signs — Service or Replace Pump If:

• Unusual noise (grinding, humming without pumping)
• Reduced flow rate despite clear screen
• Motor fails to start or trips circuit breaker
• Visible oil leaking from motor housing (indicates seal failure)
• Excessive vibration during operation
• Power cord or plug damage

Oil-Filled Motor:

The motor is factory-filled with dielectric oil for thermal protection and continuous bearing lubrication. This is a sealed system — no user maintenance is required or possible. Oil leakage from the motor indicates seal failure and the pump should be replaced.

Winterization:

If the pump will be exposed to freezing temperatures, remove it from the water and drain completely. Store in a dry location above freezing. Do not allow water to remain inside the pump housing during freezing conditions, as ice expansion can damage internal components.

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🎯 Ideal Applications

Application	Suitability	Notes
💧 Pool cover water removal	✅ Yes	Removes standing water from pool covers
💧 Pool/spa draining	✅ Yes	Drains pools, spas, and hot tubs (max 120°F liquid)
💧 Water features & fountains	✅ Yes	Ideal for statuary fountains and water displays
💧 Water transfer & recirculation	✅ Yes	Moves water between tanks, containers, or areas
⚙️ Machine tool coolant	✅ Yes	Recirculates coolant in industrial applications
⚙️ Air conditioning condensate	✅ Yes	Removes condensate from AC systems
💧 Shallow flood removal	✅ Yes	Operates down to 1/8″ water depth
♨️ Spa/hot tub jet pump	❌ No	Not designed for jet pump applications
🔄 Continuous spa circulation	❌ No	Not a circulation pump; designed for transfer/recirculation

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❓ Frequently Asked Questions

Q: What is the horsepower of this pump? A: The Little Giant 3E-34N is rated at 1/15 HP with an oil-filled, direct-drive motor operating at 115V/60Hz.

Q: Can this pump be used submerged AND in-line? A: Yes. The 3E-34N is a true dual-purpose pump. It can operate fully submerged in liquid or mounted in-line, fed by pipe or hose through the 3/4″ MNPT intake.

Q: What is the maximum water temperature this pump can handle? A: The 3E-34N is rated for liquids up to 120°F (49°C), making it suitable for draining hot tubs and spas.

Q: What size are the connections? A: The discharge port is 1/2″ MNPT and the intake port is 3/4″ MNPT. Both use standard National Pipe Thread connections.

Q: How much water can this pump move? A: At 1 foot of lift, the pump delivers 670 GPH (11.1 GPM). At 5 feet of lift, it delivers 575 GPH. At 10 feet of lift, it delivers 460 GPH. Maximum shut-off head is 20.3 feet.

Q: Does the motor require lubrication? A: No. The motor is factory-filled with dielectric oil for lifetime bearing lubrication and thermal protection. No user maintenance is required on the motor.

Q: Can I use this to drain my hot tub? A: Yes, the 3E-34N is well-suited for draining hot tubs and spas. It can handle water temperatures up to 120°F and operates down to 1/8″ water depth for thorough draining.

Q: What is the cord length? A: The pump includes a 10-foot power cord with a 3-prong grounded plug.

Q: Is this pump self-priming? A: When used as a submersible pump, no priming is needed as the pump is submerged in liquid. When used in-line, the pump must be gravity-fed or have a flooded suction to operate properly.

Q: Do I need GFCI protection? A: Yes. GFCI protection is required by the National Electrical Code (NEC) for all pool, spa, hot tub, and outdoor water feature installations.

Q: What is the difference between the 3E-34N and the 4E-34N? A: The 4E-34N (Part No. 504103) is a slightly more powerful pump rated at 1/12 HP with 710 GPH flow rate and a 6-foot cord. The 3E-34N delivers 670 GPH with a 10-foot cord.

📥 Downloads & Resources

📄 3E-34N Series Spec Sheet – Complete specifications and performance curves

📄 3E & 4E Series Installation Manual – Installation instructions, wiring, and maintenance

🏆 Why Choose the Little Giant 3E-34N

✅ Proven Reliability – Little Giant (Franklin Electric) has been manufacturing pumps for over 80 years, delivering trusted performance across residential, commercial, and industrial applications

✅ Oil-Filled Motor Technology – Factory-sealed dielectric oil provides superior thermal protection and lifetime bearing lubrication, extending pump life

✅ True Dual-Purpose Versatility – Operate submerged or in-line for maximum application flexibility

✅ Corrosion-Resistant Construction – Epoxy-coated aluminum housing, stainless steel backplate, and nylon volute resist deterioration in wet environments

✅ Compact Design – Measuring just 5.5″ × 7″ × 8.25″, the 3E-34N fits in tight spaces while delivering powerful 670 GPH performance

✅ Chemical-Resistant Shaft Seal – FKM/Viton seal handles a wide range of liquid types for industrial versatility

✅ UL Listed – Independently certified for safety compliance

🤝 Why Buy From Parts4Tubs

✅ US-based support for American customers

✅ Fast shipping across the United States

✅ Expert advice from pool, spa, and water feature specialists

✅ Competitive pricing

✅ Full warranty support

✅ Hassle-free returns

✅ Replacement volutes, gaskets, and parts available

✅ Dedicated customer service team

⭐ Summary

The Little Giant 3E-34N (503603) is a 1/15 HP oil-filled dual-purpose submersible pump delivering 670 GPH at 1 foot of lift with a 20.3-foot maximum shut-off head. Featuring an epoxy-coated aluminum housing, stainless steel backplate, FKM/Viton shaft seal, and polypropylene debris screen, this UL-listed pump operates submerged or in-line at 115V/60Hz with a 10-foot power cord. Handles liquids up to 120°F, making it ideal for hot tub draining, pool cover removal, water features, and industrial liquid transfer. Order today from Parts4Tubs for fast US shipping and expert support.

How do I Replace a Hot Tub Pump?

Here's a general step-by-step guide on how to replace a hot tub pump. Keep in mind that the specific steps may vary depending on your hot tub's make and model, so it's essential to consult your hot tub's manual for model-specific instructions. If you're not comfortable with this procedure, it's a good idea to seek professional assistance.

Materials You'll Need:

• Replacement pump
• Pipe wrench
• Adjustable wrench
• Screwdriver
• Pipe sealant (thread tape or plumber's putty)
• PVC primer and cement (if you have PVC plumbing)
• Teflon tape (for threaded connections)

Procedure:

1. Turn Off the Power: Before you begin, ensure the hot tub's power supply is turned off at the circuit breaker or disconnect switch. Safety should always be a priority when working with electrical components.

2. Drain the Hot Tub: If your hot tub is not already empty, you'll need to drain it. Follow your hot tub's manual or manufacturer's instructions for proper draining. (You might not need to do this if you can lock the pump off with the gate valves)

3. Locate the Pump: Identify the location of the existing pump in your hot tub. It's usually located near the equipment area or in a designated pump compartment.

4. Disconnect the Electrical Wiring: Carefully disconnect the electrical wiring from the old pump. This typically involves removing the electrical conduit cover, unscrewing wire nuts, and disconnecting the wires from the terminals. Be sure to note the wire connections or take a picture for reference when connecting the new pump.

5. Disconnect the Plumbing: Depending on your hot tub's plumbing setup, you'll need to disconnect the plumbing connections to the pump. Use a pipe wrench or adjustable wrench to loosen and remove the fittings. Be prepared for some water spillage when disconnecting the plumbing.

6. Remove the Old Pump: Once the electrical and plumbing connections are detached, carefully remove the old pump from its mounting position. Some pumps may be secured with mounting brackets or bolts.

7. Prepare the New Pump: If the new pump is not pre-assembled, you may need to attach fittings, unions, or adapters to match your hot tub's plumbing. Ensure that you use the appropriate sealant or Teflon tape on threaded connections to prevent leaks.

8. Mount the New Pump: Position the new pump in the same location as the old one and secure it in place using the mounting brackets or bolts.

9. Reconnect Plumbing: Reconnect the plumbing to the new pump, ensuring that all connections are tight and secure. If your hot tub uses PVC plumbing, use PVC primer and cement to bond the connections properly.

10. Reconnect Electrical Wiring: Reconnect the electrical wiring to the new pump, following the notes or pictures you took earlier. Make sure all wires are properly connected and secure.

11. Turn On the Power: Restore power to the hot tub by switching on the circuit breaker or reconnecting the disconnect switch.

12. Test the Pump: Turn on the hot tub's pump to ensure that it's working correctly. Check for any signs of leaks or irregularities in the plumbing connections.

13. Refill the Hot Tub: Once you've confirmed that the new pump is functioning properly, refill the hot tub with water.

14. Check for Leaks: Inspect the plumbing connections for any leaks. If you find any, turn off the pump, drain the tub again, and reseal the connections as needed.

15. Monitor: Keep an eye on the pump and plumbing for the next few days to ensure everything is functioning correctly and that there are no further issues.

Remember that this is a general guideline, and the specific steps may vary based on your hot tub's design. If you're unsure or uncomfortable with any aspect of this process, please do get in touch, happy to help.

How do I know what size hot tub pump I have?

Determining the size of your hot tub pump is an important step when it comes to maintenance or replacement. To find out the size of your hot tub pump, follow these steps:

1. Check the Manual: The easiest way to determine the size of your hot tub pump is to consult the owner's manual or user documentation that came with your hot tub. The manual typically contains detailed information about the specifications and components of your hot tub, including the pump.

2. Look at the Pump Housing: If you don't have access to the manual or it doesn't provide the information you need, inspect the pump itself. Most hot tub pumps have a label or plate on the pump housing that displays essential details, including the pump's model number, manufacturer, and specifications. You can then send that to me or Google it.

3. Measure the Pump: If the label is missing or damaged, you can measure the pump's dimensions. Measure the diameter of the pump's wet end (the part where the water flows) and the length of the wet end. These measurements can help identify the size and capacity of the pump.

4. Consult the Manufacturer: If you can't find the information on the pump or in the manual, contact the hot tub manufacturer or a reputable dealer. Provide them with your hot tub's model and serial number, and they should be able to identify the correct pump size for your specific hot tub.

5. Online Research: You can also search online using the pump's model number or hot tub's make and model. Many manufacturers provide detailed information about their products on their websites, and you may find specifications for your pump model.

Once you have determined the size and specifications of your hot tub pump, you can proceed with maintenance, repairs, or replacement if necessary. Keep in mind that replacing a hot tub pump with the same size and capacity as the original is crucial to ensure proper water circulation and filtration in your hot tub. If you're unsure about any aspect of this process, get in touch, always happy to help.