♨️ LX WP500-II Spa Pump – 5HP Dual Speed Jet Pump
Maximum Dual-Speed Power for the Most Demanding Spa Applications
💦 Product Overview
The LX WP500-II is the flagship dual-speed pump in the LX WP series, delivering an impressive 5.0HP of power for demanding water circulation and jet operation in large hot tubs and swim spas. As the most powerful dual-speed pump in the range, the WP500-II combines exceptional high-speed jet performance with efficient low-speed circulation in a single unit.
This powerhouse pump features a substantial 3.67kW motor with dual-speed operation, drawing 15A on high speed for maximum jet thrust and just 4.5A on low speed for quiet, energy-efficient circulation. The larger 2.5-inch union connections accommodate the increased water flow required for high-performance spa systems, making the WP500-II ideal for large swim spas, commercial installations, and premium residential hot tubs with extensive jet configurations.
Supplied with a 4-core plain cable for straightforward dual-speed wiring, the WP500-II offers professional-grade performance in a compact package measuring 458mm × 209mm × 261mm. Commonly found in Chinese-manufactured spas, Coasts spas, and select Jacuzzi models, this pump is the definitive choice for spa owners who refuse to compromise on power or versatility.
⭐ Key Features
✅ 5.0HP Dual-Speed Motor – The most powerful dual-speed pump in the LX WP series with 3.67kW output
✅ Dual-Speed Operation – High speed for powerful jets, low speed for quiet filtration and heating
✅ High Speed Performance – 15A draw delivers maximum jet power for intensive hydrotherapy
✅ Energy-Efficient Low Speed – Just 4.5A for economical continuous circulation
✅ 2.5″ Union Connections – Larger plumbing for increased flow capacity
✅ 50µF Capacitor – Heavy-duty capacitor for reliable motor starting under load
✅ 4-Core Cable Supplied – Pre-wired for straightforward dual-speed installation
✅ Compact Dimensions – 458mm × 209mm × 261mm fits most equipment bays
✅ Massage Pump Design – Optimised for powerful jet operation and water circulation
✅ Proven Compatibility – Works with Chinese spas, Coasts spas, and Jacuzzi models
⚙️ Technical Specifications
Motor Specifications
| Specification | Value |
|---|---|
| Power Reference | 5.0 HP |
| Motor Output | 3.67 kW |
| Speed Type | Dual Speed (2 Speed) |
| Capacitor | 50 µF |
Amperage by Speed
| Speed Setting | Amperage |
|---|---|
| High Speed | 15.0 A |
| Low Speed | 4.5 A |
Physical Dimensions
| Specification | Value |
|---|---|
| Length | 458 mm |
| Width | 209 mm |
| Height | 261 mm |
| Plumbing Size | 2.5″ |
Connection Specifications
| Specification | Value |
|---|---|
| Plumbing Connections | 2.5-inch unions |
| Electrical Cable | 4-core plain cable (supplied) |
| Speed Type | 2 Speed |
| Pump Type | Massage Pump |
🔌 Electrical Requirements
| Electrical Specification | Requirement |
|---|---|
| High Speed Amperage | 15.0 A |
| Low Speed Amperage | 4.5 A |
| Capacitor Rating | 50 µF |
| Cable Type | 4-core plain cable (supplied) |
Understanding 4-Core Dual-Speed Wiring
The WP500-II is supplied with a 4-core cable for dual-speed operation:
| Wire | Function |
|---|---|
| Live 1 | High Speed |
| Live 2 | Low Speed |
| Neutral | Common Neutral |
| Earth | Protective Earth |
💡 Tip: LX pumps typically use Black for High Speed and Brown for Low Speed, which may be reversed from other pump brands. Always verify wire functions before connecting to your control system.
⚠️ IMPORTANT ELECTRICAL SAFETY NOTICE:
All electrical work must be carried out by a qualified electrician in accordance with UK wiring regulations (BS 7671). Hot tub installations require RCD protection (30mA) for safety. Never attempt electrical connections yourself unless you are appropriately qualified.
⚠️ High amperage requirement – At 15A on high speed, this pump requires a suitably rated circuit and breaker. A dedicated circuit is typically required for pumps of this size.
💧 Compatibility Guide
Plumbing Configuration
| Component | Specification |
|---|---|
| Plumbing Size | 2.5″ |
| Connection Type | 2.5-inch unions |
💡 Note: The WP500-II uses larger 2.5″ plumbing connections compared to the 2″ connections on smaller WP series pumps. Ensure your plumbing system is compatible or appropriate adaptors are used.
Compatible Hot Tub Brands
The LX WP500-II is commonly found in and compatible with:
- ♨️ Chinese-manufactured hot tubs and swim spas
- ♨️ Coasts Spas (not the American “Coast Spas”)
- ♨️ Select Jacuzzi models
🛠️ Installation Requirements
Mounting Specifications
| Requirement | Specification |
|---|---|
| Dimensions (L × W × H) | 458mm × 209mm × 261mm |
| Base Surface | Solid, level, vibration-dampening |
| Ventilation | Ensure adequate clearance for motor cooling |
Plumbing Connections
| Connection | Size |
|---|---|
| Plumbing | 2.5″ unions |
Installation Notes
⚠️ Pump must be installed below water level (flooded suction) – This ensures proper priming and prevents air lock issues.
⚠️ Never run the pump dry – Dry running causes immediate seal damage and may destroy the pump. Always ensure water is present before starting.
⚠️ Ensure proper electrical bonding to earth – All metal components must be correctly earthed as per BS 7671 requirements.
⚠️ 4-core wiring required – Dual-speed operation requires proper connection of both speed wires to your spa control system.
⚠️ Check wire colours – LX wiring colours may differ from other brands. Black typically = High Speed, Brown typically = Low Speed. Verify before connecting.
⚠️ Higher amperage circuit – At 15A high speed draw, ensure your electrical circuit is appropriately rated. A dedicated circuit is recommended.
🔄 Maintenance Guide
Routine Maintenance Schedule
| Task | Frequency | Notes |
|---|---|---|
| Check for water leaks | Monthly | Inspect around seal area and union connections |
| Inspect union connections | Monthly | Tighten if any looseness detected |
| Check motor vents | Quarterly | Ensure vents are clear of debris for proper cooling |
| Inspect mounting bolts | Quarterly | Tighten if loose to reduce vibration |
| Listen for unusual sounds | Monthly | Early detection of bearing or impeller issues |
| Check amperage draw | Annually | Should read approximately 15A (high) / 4.5A (low) |
| Test both speeds | Monthly | Ensure smooth transition between speeds |
Warning Signs – When to Replace
Consider replacing your pump if you notice:
- 🔊 Unusual noises such as grinding, screeching, or humming
- 💧 Water leaking from the mechanical seal area
- ⚡ Motor repeatedly tripping the circuit breaker
- 💨 Significantly reduced water flow from jets
- 🌡️ Motor housing becoming excessively hot to touch
- ⏱️ Pump struggling to start or humming without turning
- 🔄 One speed failing while the other works (capacitor or winding issue)
🎯 Ideal Applications
| Application | Suitability | Notes |
|---|---|---|
| ♨️ Large Hot Tub Jets | ✅ Excellent | 5HP delivers maximum jet power |
| ♨️ Swim Spa Jet Systems | ✅ Excellent | High flow for demanding swim current |
| ♨️ Multi-Jet Configurations | ✅ Excellent | Powers extensive jet layouts |
| ♨️ Combined Jet & Circulation | ✅ Excellent | Dual-speed handles both duties |
| ♨️ Commercial Installations | ✅ Excellent | Professional-grade reliability |
| 🛁 Standard Home Hot Tubs | ⚠️ May be oversized | Consider WP200-II or WP300-II |
❓ Frequently Asked Questions
Q: What horsepower is this pump?
A: The WP500-II is rated at 5.0HP with a 3.67kW motor output – the most powerful dual-speed pump in the LX WP series.
Q: Is this a single or dual speed pump?
A: This is a dual-speed pump (2 speed). High speed provides maximum jet power at 15A, while low speed runs efficiently at 4.5A for circulation and heating.
Q: Will this pump fit my hot tub?
A: This pump has 2.5-inch plumbing connections (larger than the standard 2″ on smaller pumps) and dimensions of 458mm × 209mm × 261mm. Check your existing pump’s connection size and available space for compatibility.
Q: What is the amperage draw?
A: The pump draws 15.0A on high speed and 4.5A on low speed. Ensure your electrical circuit is appropriately rated for the high-speed draw.
Q: What size are the plumbing connections?
A: 2.5-inch unions are used for both suction and discharge connections. This is larger than the 2″ connections on smaller WP series pumps.
Q: What capacitor does this pump use?
A: The pump uses a 50µF capacitor – larger than smaller WP pumps to handle the increased motor power.
Q: Which hot tub brands is this compatible with?
A: The WP500-II is compatible with Chinese-manufactured spas, Coasts spas (not the American “Coast Spas”), and some Jacuzzi models.
Q: How does this compare to the WP400-I?
A: The WP500-II is a 5HP dual-speed pump, while the WP400-I is a 4HP single-speed pump. The WP500-II offers both high-power jets AND efficient low-speed circulation, whereas the WP400-I runs at full power only. The WP500-II also has larger 2.5″ connections vs 2″ on the WP400-I.
Q: What’s the difference between the WP300-II and WP500-II?
A: The WP500-II delivers 5HP/3.67kW compared to 3HP on the WP300-II. The WP500-II has larger 2.5″ plumbing connections and higher amperage (15A vs approximately 10A). Choose the WP500-II for large spas, swim spas, or systems requiring maximum flow.
Q: How do I know if my pump needs replacing?
A: Common signs include unusual grinding or screeching noises, water leaking from the seal area, reduced jet flow, the motor tripping the breaker repeatedly, one speed failing, or the pump struggling to start.
🏆 Why Choose the LX WP500-II
✅ Maximum Power – 5.0HP / 3.67kW is the most powerful dual-speed pump in the LX range
✅ Dual-Speed Versatility – High speed jets (15A) plus efficient low speed circulation (4.5A)
✅ Large Flow Capacity – 2.5″ unions accommodate high-volume water flow
✅ Heavy-Duty Construction – Built for demanding commercial and residential applications
✅ Ready to Install – Supplied with 4-core cable and union connections
✅ Proven Compatibility – Works with Chinese spas, Coasts spas, and Jacuzzi models
✅ Energy Efficient – Low speed operation minimises running costs during filtration
🤝 Why Buy from Parts4Tubs
✅ UK-Based Company – Local support from spa parts specialists who understand your needs
✅ Fast UK Delivery – Quick dispatch to get your hot tub back up and running promptly
✅ Expert Technical Advice – Knowledgeable team available to help with compatibility questions and installation guidance
✅ Competitive Pricing – Great value on genuine quality parts without compromising on reliability
✅ Full Warranty Support – Peace of mind with comprehensive warranty coverage
✅ Easy Returns – Hassle-free returns within 30 days if you’re not completely satisfied
✅ Replacement Parts Available – Seal kits, capacitors, and other spares in stock
✅ Real People, Real Help – Buy from a person, not just the internet. We’re here to help with your spa parts needs
✨ Summary
The LX WP500-II is the ultimate 5.0HP dual-speed massage pump for large hot tubs, swim spas, and demanding applications requiring maximum power and versatility. With its robust 3.67kW motor delivering 15A on high speed for powerful jets and just 4.5A on low speed for efficient circulation, this pump handles both duties with ease. Featuring larger 2.5-inch union connections for high-volume flow, a 50µF capacitor for reliable starting, and compact 458mm × 209mm × 261mm dimensions, the WP500-II is engineered for professional-grade performance. Compatible with Chinese spas, Coasts spas, and select Jacuzzi models, the WP500-II is the definitive choice for spa owners who demand the best in dual-speed power and efficiency.
The hot tub industry doesnt make it easy for you when you are trying to match up the size of the unions (the part that screws your pipe work onto the pumps) Below you can see the physical sizes of the collars, and how they relate to the actual union size you need. So a measurement of 2.5", edge to edge on the collar of the pump is actually a 1.5" union - confusing - absolutely! If you are not sure, give me a shout!
Hot Tub Pump Collar & Union Size Chart
| 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
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:
- 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.
- 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)
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Turn On the Power: Restore power to the hot tub by switching on the circuit breaker or reconnecting the disconnect switch.
- 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.
- Refill the Hot Tub: Once you've confirmed that the new pump is functioning properly, refill the hot tub with water.
- 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.
- 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:
- 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.
- 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.
- 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.
- 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.
- 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.









