🛁 Sundance Jacuzzi NB1 TheraMax Spa Pump 6500-091 – 2.5 HP Single-Speed 230V

Reliable OEM jet pump power engineered for Sundance and Jacuzzi hot tubs

📋 Product Overview

The Sundance/Jacuzzi NB1 TheraMax 6500-091 is a factory OEM 2.5 HP single-speed jet pump designed specifically for Sundance and Jacuzzi spa systems. Built by LX (Lingxiao) to Sundance/Jacuzzi specifications, this 48-frame pump delivers consistent, powerful jet performance at 230V/60Hz with a 10.0 Amp draw. The innovative baseless (bracketless) design allows the pump to be mounted using the separate 6000-532 bracket, which straps around the motor casing and can be adjusted to accommodate virtually any plumbing setup. The rotatable wet end can be repositioned to match your existing plumbing configuration, making this an exceptionally versatile replacement pump. The 6500-091 is the current updated replacement for numerous legacy Sundance TheraMax and TheraFlo pump part numbers dating back to 1997, serving as a direct drop-in replacement across a wide range of Sundance 850/880 series and Jacuzzi J-300 series spa models.

✨ Key Features

✅ OEM Factory Pump – Genuine Sundance/Jacuzzi replacement pump manufactured by LX (Lingxiao) to OEM specifications

✅ 2.5 HP Single-Speed Motor – 2.5 HP continuous duty rated motor provides powerful, consistent jet performance for hydrotherapy

✅ 230V / 60Hz Operation – North American electrical standard with 10.0 Amp draw for efficient single-speed operation

✅ 48-Frame Construction – Industry-standard 48Y frame for broad compatibility with Sundance and Jacuzzi spa equipment bays

✅ Baseless / Bracketless Design – No integrated feet; mounts using the separate 6000-532 bracket that wraps around the motor body for maximum installation flexibility

✅ Rotatable Wet End – Wet end can be rotated to left or right positions to align with existing plumbing configurations, eliminating the need for plumbing modifications

✅ 2″ MBT Connections – Both suction (center) and discharge (side) ports use 2″ Male Buttress Thread (MBT) connections with 3-1/16″ outer thread dimensions

✅ Side Discharge Configuration – Side discharge design optimized for Sundance/Jacuzzi equipment bay layouts

✅ Wide Model Compatibility – Replaces numerous legacy TheraMax, TheraFlo, and Aqua-Flo XP pump part numbers from 1997 to present

✅ Universal Replacement – Compatible with Sundance 850/880 series and Jacuzzi J-300 series spa models

✅ 1-Year Manufacturer Warranty – Backed by manufacturer’s limited warranty for parts

⚙️ Technical Specifications

Specification	Value
Pump Series	NB1 TheraMax
Manufacturer	LX (Lingxiao) for Sundance/Jacuzzi
OEM Part Number	6500-091
Horsepower (Continuous)	2.5 HP
Speed Settings	Single Speed (1-Speed)
Voltage	230V
Frequency	60 Hz
Amperage	10.0 Amps
Frame Type	48Y (48 Frame)
Discharge Location	Side
Discharge Size	2″ MBT (Male Buttress Thread)
Suction Size	2″ MBT (Male Buttress Thread)
Thread OD (Outer Thread)	3-1/16″ (inlet and outlet)
Motor Base	Baseless (No Feet) – Bracket Required
Mounting Bracket	6000-532 (Sold Separately)
Cord Type	NONE (Not Included)
Wet End Rotation	Adjustable (Rotatable to match plumbing)
Warranty	1-Year Manufacturer’s Limited
UPC	682318852627

⚠️ Note on HP Ratings: In the spa pump industry, horsepower can be expressed using different rating methods. This pump is rated at 2.5 HP continuous duty. Some sources may reference a higher “uprated” or “brake” HP figure (4.2 HP) which represents peak input power under specific test conditions. The 2.5 HP continuous rating reflects the pump’s sustained operating output and is the standard industry specification used for pump selection and replacement.

⚡ Electrical Requirements

Electrical Spec	Requirement
Supply Voltage	230V
Frequency	60 Hz
Phase	Single Phase
Full Load Amps	10.0 A
Cord	Not Included – Use existing cord or purchase separately

⚠️ IMPORTANT ELECTRICAL SAFETY:

All electrical work must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and local building codes. Hot tubs require GFCI (Ground Fault Circuit Interrupter) protection. A dedicated circuit is required – do not share with other appliances. Verify your spa’s voltage before ordering. Using the wrong voltage will damage the motor and void the warranty. This pump does not include a power cord – use your existing AMP cord or purchase a compatible 1-speed AMP cord (such as part #21086) separately.

🔗 Compatibility Guide

Frame & Port Configuration

Specification	Detail
Frame	48 Frame (48Y)
Discharge	2″ MBT – Side
Suction	2″ MBT – Center
Thread OD	3-1/16″ (outside thread to outside thread)
Motor Base	Baseless – Requires 6000-532 bracket

Compatible Sundance Spa Models

This pump (6500-091 / 6500-341) is the factory OEM replacement used on the following Sundance spa models (1997-Present):

• Altamar
• Bahia
• Calypso / Calypso II
• Cameo
• Certa
• Chelsee
• Hamilton
• Hartford
• Hawthorne
• Madison
• Majesta
• Marin
• Maxxus (#2 and #3 pump)
• Montego
• Optima
• Palermo
• Telluride

Compatible Jacuzzi Spa Models

• J-325, J-330, J-335, J-340, J-345
• J-350, J-355, J-360, J-365
• J-370, J-375, J-380, J-385

Replaces These Legacy Sundance Part Numbers

This pump is the current replacement for the following older TheraMax, TheraFlo, and Aqua-Flo XP pump part numbers:

• 6500-126
• 6500-131
• 6500-263
• 6500-266
• 6500-269
• 6500-341 (previous current version)
• 6500-349
• 6500-763
• 6500-766
• 6500-767
• 6500-769
• 06020194-2
• T55SWBNC-999

💡 Pump History: From 1994-1996, Sundance Spas used the Vico “Ultra Jet” pump. Starting in 1997, Sundance transitioned to Aqua-Flo “XP” series pumps branded as TheraFlo and TheraMax. The current NB1 series (manufactured by LX) is the latest evolution of this pump line and serves as a universal replacement for all previous versions.

🔩 Alternate Part Numbers

This pump may be listed under the following part numbers across different retailers and distributors:

• 6500-091 (Current OEM Part Number)
• SD6500-091
• 6500091
• SD6500091
• SD-6500-091
• SD-6500091
• 34-343-3070
• 6500-767
• LX NB1
• 6500-341 (Previous Part Number)
• 6500-349
• 6500-097
• 4234110-S

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🛠️ Installation Requirements

Mounting

Requirement	Specification
Mounting Type	Baseless – Requires 6000-532 bracket
Bracket	Wraps around motor body, mounts to equipment bay
Position	Horizontal
Base	Solid, level, vibration-dampening surface
Ventilation	Minimum 6 inches clearance around motor for cooling
Access	Sufficient clearance for maintenance and wet end rotation

Plumbing

Connection	Size
Suction	2″ MBT (Center)
Discharge	2″ MBT (Side)
Thread OD	3-1/16″
Unions	Use standard 2″ pump unions (sold separately)

Installation Notes

⚠️ Pump must be installed below water level (flooded suction) to ensure proper priming

⚠️ Never run pump dry – causes mechanical seal damage and motor overheating

⚠️ Ensure proper grounding and bonding per NEC requirements – use at least No. 8 AWG solid copper bonding wire

⚠️ GFCI protection is required by code for all hot tub and spa installations

⚠️ This pump does not include a power cord – reuse your existing cord or purchase a compatible 1-speed AMP cord separately

⚠️ Mounting bracket (6000-532) is sold separately – you may reuse your existing bracket if in good condition

💡 Wet End Rotation: The wet end can be rotated to align with your existing plumbing. Loosen the through-bolts on the back of the pump, rotate the wet end to the desired position, and retighten the bolts securely.

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🔄 Maintenance Guide

Routine Maintenance

Task	Frequency	Notes
Check for leaks	Monthly	Inspect around mechanical seal and union connections
Inspect unions	Monthly	Tighten if needed; replace O-rings if leaking
Clean strainer/filter	As needed	Remove debris to maintain proper flow
Check amperage draw	Annually	Should read approximately 10.0 A; higher readings indicate potential issues
Inspect motor vents	Quarterly	Keep clear of debris for proper cooling
Check mounting bracket	Quarterly	Ensure bracket is secure and motor is not shifting

Warning Signs – Replace Pump If:

• Unusual noise (grinding, screeching, or humming without rotation)
• Water leaking from the mechanical seal area
• Motor repeatedly trips the circuit breaker
• Noticeably reduced water flow or weak jets
• Motor overheating or burning smell
• Visible corrosion or damage to the wet end

Seal Replacement

Detail	Specification
Seal Type	Mechanical Seal
Replacement	Replace at first sign of leakage from the seal area

⚠️ When replacing the seal, also inspect the impeller and volute for wear or damage. A worn impeller will reduce pump performance even with a new seal.

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🎯 Ideal Applications

Application	Suitability	Notes
♨️ Hot tub jet pump	✅ Yes	Primary application – designed as a jet pump for Sundance and Jacuzzi spas
♨️ Secondary jet pump	✅ Yes	Used as the secondary (1-speed) jet pump in multi-pump Sundance configurations
🛁 Whirlpool bath	⚠️ Check compatibility	May work in whirlpool applications with matching frame and port specifications

💡 Usage Note: In Sundance spa systems, this 1-speed pump is typically used as the secondary jet pump. For the primary 2-speed pump, see the Sundance 6500-343 (2-speed version).

❓ Frequently Asked Questions

Q: What horsepower is this pump? A: This pump is rated at 2.5 HP continuous duty. Some industry sources may also reference a 4.2 HP “uprated” or “brake” HP figure, which represents peak input power. The 2.5 HP continuous rating is the standard specification used for pump selection.

Q: Will this fit my Sundance or Jacuzzi hot tub? A: This pump is the factory OEM replacement for numerous Sundance 850/880 series models and Jacuzzi J-300 series models from 1997 to present. Verify your existing pump’s frame size (48 frame), port sizes (2″ MBT), and voltage (230V) before ordering. Check the compatibility list above for your specific spa model.

Q: What voltage does this pump require? A: 230V / 60Hz single phase. All electrical installation must be performed by a licensed electrician. Verify your spa’s voltage before ordering.

Q: Does this pump come with a power cord? A: No, this pump does not include a power cord. You can reuse your existing AMP cord from your old pump, or purchase a compatible 1-speed AMP cord (such as part #21086) separately.

Q: Does this pump come with a mounting bracket? A: No, the mounting bracket (part #6000-532) is sold separately. This is a baseless pump that requires the bracket which wraps around the motor body. You may reuse your existing bracket if it is in good condition.

Q: Can I rotate the wet end to match my plumbing? A: Yes, the wet end is fully rotatable. Loosen the through-bolts on the rear of the pump, rotate the wet end to align with your existing suction and discharge plumbing, and retighten the bolts securely.

Q: What is the difference between 6500-091 and 6500-341? A: The 6500-091 is the current updated part number that replaces the older 6500-341. They are functionally the same pump. The 6500-091 is the latest version you will receive when ordering.

Q: Is this pump 1-speed or 2-speed? A: This is a single-speed (1-speed) pump. It is typically used as the secondary jet pump in Sundance spa systems. For the 2-speed primary pump, see part number 6500-343 (or the equivalent 6500-092).

Q: What size are the ports? A: Both the suction (center) and discharge (side) ports are 2″ MBT (Male Buttress Thread). The outer thread dimension measures 3-1/16″ from outside thread to outside thread.

Q: What size unions do I need? A: This pump uses standard 2″ pump unions. The union collar measures approximately 3.1″ (78mm) tip to tip. Standard 2″ FBT (Female Buttress Thread) unions with O-rings are compatible.

Q: What warranty is included? A: This pump includes a 1-year manufacturer’s limited warranty on parts. Contact Parts4Tubs for full warranty terms and conditions.

Q: How do I know if my pump needs replacing? A: Common signs include unusual noise (grinding, screeching), water leaking from the seal area, reduced water flow or weak jets, the motor tripping the circuit breaker, or the motor overheating.

Q: Do I need a GFCI breaker? A: Yes, GFCI (Ground Fault Circuit Interrupter) protection is required by the National Electrical Code (NEC) for all hot tub and spa installations.

Q: Will this replace my old Aqua-Flo XP or TheraMax pump? A: Yes, this is the current factory replacement for all previous Sundance TheraMax, TheraFlo, and Aqua-Flo XP pump models used in Sundance spas from 1997 onward. See the full list of replaced part numbers in the Compatibility Guide above.

🏆 Why Choose the Sundance 6500-091 NB1 TheraMax

✅ Factory OEM Replacement – Genuine Sundance/Jacuzzi specification pump ensuring exact fit and performance

✅ Powerful 2.5 HP Motor – Delivers strong, consistent jet pressure for a satisfying hydrotherapy experience

✅ Universal Installation Flexibility – Baseless design with rotatable wet end adapts to any existing plumbing configuration

✅ Broad Compatibility – Replaces dozens of legacy pump part numbers across Sundance and Jacuzzi spa models from 1997 to present

✅ Proven LX Manufacturing – Built by Lingxiao, a trusted global manufacturer of spa pumps with extensive industry experience

✅ 1-Year Manufacturer Warranty – Backed by manufacturer’s limited warranty for peace of mind

🤝 Why Buy From Parts4Tubs

✅ US-based support for American customers

✅ Fast shipping across the United States

✅ Expert advice from spa and hot tub specialists

✅ Competitive pricing in USD

✅ Full warranty support

✅ Hassle-free returns

✅ Replacement seals, unions, and AMP cords available

✅ Dedicated customer service team

✨ Summary

The Sundance/Jacuzzi 6500-091 NB1 TheraMax is a 2.5 HP single-speed, 230V/60Hz OEM jet pump built for Sundance 850/880 series and Jacuzzi J-300 series spas. Featuring a 48-frame baseless design with a rotatable wet end, 2″ MBT connections, and 10.0 Amp draw, this pump replaces all previous TheraMax, TheraFlo, and Aqua-Flo XP models from 1997 to present. Backed by a 1-year warranty and available now at Parts4Tubs with expert compatibility support

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	Magic Plastics Union 0602-15 (1.5″ Pump Union) | 1-1/2″S x 1-1/2″FBT Union, Pump, Magic, 1-1/2"S x 1-1/2"FBT (Industry Standard) w/ O-Ring	$6.36 Max: 575 Min: 1 Step: 1 Add to cart
	Magic Plastics Union 0602-20 (2″ Pump Union) | 2″S x 2″FBT w/ O-Ring Union, Pump, Magic, 2"S x 2"FBT (Industry Standard) w/ O-Ring	$8.00 Max: 501 Min: 1 Step: 1 Add to cart
	Waterway Union 400-6010 | 2-1/2″ Union Nut with 2-1/2″ Slip tailpiece and o-ring (2.5″ union) Union, Pump, Waterway, 2-1/2"FBT x 2-1/2"S	$14.77 Max: 145 Min: 1 Step: 1 Add to cart
	1 Speed Pump / Blower / AMP Cord | 21086 Amp Plug, Pump, 1-Speed, 14/3, 4-Pin, 5' Cord, White	$24.71 Max: 377 Min: 1 Step: 1 Add to cart
	Balboa Amp Plug 21087 (For 2 Speed Pumps) Amp Plug, Pump 1 (2-Speed) 14/4, 72" Long, White	$31.72 Max: 182 Min: 1 Step: 1 Add to cart

Hot Tub Pump Collar & Union Size Chart

Imperial & Metric Specifications

Union Size	Collar Size	Thread OD	Union OD	O-Ring Size
1.5" Female Buttress Thread (FBT)	2.5" / 64mm (Tip to Tip) Measurement	2-1/2" 64mm	2-13/16" 71mm	2-5/16" OD 59mm
2" Female Buttress Thread (FBT)	3.1" / 78mm (Tip to Tip) Measurement	3-1/16" 78mm	3-3/8" 81mm	2-15/16" OD 75mm
2.5" Female Buttress Thread (FBT)	3.6" / 91mm (Tip to Tip) Measurement	3-5/8" 91mm	4-1/4" 108mm	3-7/16" OD 87mm

Important Notes

The union "size" (1.5", 2", 2.5") is nominal and doesn't correspond to any actual measurement.

Collar size is measured from thread tip to thread tip on the pump outlet.

Most hot tub pumps use Female Buttress Thread (FBT) - 98% of applications.

O-ring gaskets may vary between manufacturers - measure your existing gasket for accuracy.

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.